Coal derived carbon-based aggregates and methods of making the same

Abstract

Embodiments of the present disclosure relate to compositions (e.g., pyrolysis char aggregates (PCA)), PCA concrete specimens, and methods of making PCA. A composition includes PC, cementitious material, superplasticizer, water, silica fume, and one or more additives. A method of forming the composition includes mixing a superplasticizer with water to form a wet mixture, mixing one or more additives, silica fume, and PC to form a dry mixture, mixing the wet mixture and the dry mixture to form a PC mixture, curing the PC mixture to form a PC block (PCB), and crushing the PCB to form a PCA. The method of forming a concrete includes mixing an air entraining agent, a water reducer, and water to form a solution, mixing a fine PCA, a course PCA, a cementitious material, water, and the solution to form a PCA concrete, and curing the PCA concrete.

Description

Attorney Docket No.: UWYO / 0131PCCOAL DERIVED CARBON-BASED AGGREGATES AND METHODS OF MAKING THE SAME BACKGROUNDField

[0001] Embodiments of the present disclosure generally relate to a pyrolysis char aggregate. More particularly, the present disclosure relates to a concrete specimens utilizing a pyrolysis char aggregate and methods of making a pyrolysis char aggregate.Description of the Related Art

[0002] Coal currently serves an important role as an energy source but the increasing demand for renewable energy has reduced the production and consumption of coal in the United States of America (USA). Coal is carbon-rich and its use in energy generation may affect atmospheric CO2 levels. The air pollution and global environmental issues associated with the combustion of coal have limited the continuous application of coal in energy production. Specifically, according to the Bureau of Safety and Environmental Enforcement (BSEE), global warming that results from various greenhouse gas emissions is partly due to fossil fuel burning, such as the combustion of coal.

[0003] Wyoming Powder River Basin (PRB) coal plays an important role in the Wyoming energy industry as well as different parts of the United States and the world more generally. Wyoming produces approximately 40% of the coal in the United States, and the coal industry contributes significant revenue to the state of Wyoming (over $798 million in 2018). However, renewable energy is slowly replacing the coal industry, causing the market price of coal to drop. Thus, to attract new investment through technological innovation and support coal mine operations, environmentally friendly methods to create new diversified coal products are needed.

[0004] Light weight aggregates (LWA) produced from industrial byproducts have been widely used to enhance performance and sustainability in concrete. Aggregates typically constitute about 70% to about 80%, by volume, of the8781485 1Attorney Docket No.: UWYO / 0131PCconcrete, making them a significant component of concrete production. Natural aggregate sources are depleting, therefore, efforts to find LWA alternatives from industrial byproducts of construction and demolition wastes are increasing. LWAs reduce dead load and enhance durability, enhance thermal mechanical, acoustic, and insulation properties of concrete. The common principle of manufacturing artificial LWAs involves agglomerating raw materials, followed by either sintering or cold bonding. Sintering involves high energy outputs, as raw materials are fused in furnaces at 1000°C to 120°C, followed by pelletization. Cold bonding uses methods of binding raw materials with cementitious binders and curing them at normal temperatures, making it more energy efficient. Other issues related to pelletization, such as loose bonding, over clustering, and slurry formation, have prompted researchers to adopt cold bonding with crushing techniques to form LWAs. Cold bonded LWAs with alkali activators and pozzolanic binders have improved mechanical and physical properties.

[0005] While naturally occurring LWAs, such as perlite, vermiculite, and rhyolite offer some potential, their limited availability, variability in properties, and the need for extensive mining and long-distance hauling often increase production costs and undermine sustainability objectives. Furthermore, many sources contain reactive siliceous components that trigger alkali-aggregate reaction (AAR). The most common reaction is alkali-silicate reaction (ASR), which occurs when reactive aggregates containing silicate react with alkali hydroxides in the presence of moisture in the pore concrete solution, producing an expansive gel that generates internal stresses and causes cracking and bond failures in the concrete. These increasing concerns regarding resource scarcity, durability, and sustainability concerns have promoted a shift to the use of alternative sources, such as industrial waste byproducts to manufacture LWAs, manufactured aggregates (e.g., from coal waste, power plant ash, or metallurgical slag), and recycled aggregates, (e.g., concrete, bricks, tires, and plastics) for the manufacture of LWAs.

[0006] Various industrial byproducts or waste materials, such as a fly ash, bottom ash, glass powder, ceramic waste, rubber, and sewage sludge, have 8781485 2Attorney Docket No.: UWYO / 0131PCbeen used in the past to produce LWAs for concrete, yielding varying results. For instance, sewage sludge-based LWC demonstrated good workability, density of 1947 kg / m3, and the 28-day compressive strength of 49.46 MPa, exceeding the 17.2 MPa minimum requirement of the ATM C330. Ceramic waste at replacement levels of 15%-25% showed improved mechanical properties and densified interfacial transition zone (ITZ) compared to normalweight concrete. In contrast, investigations on waste rubber-derived LWAs have shown a maximum compressive strength of not more than 18 MPa, indicating weak bonding between the rubber particles and the cement matrix. Among coal combustion byproducts, sintered fly ash aggregates have reduced concrete density by up to 22% and increased compressive strength by 20%, enabling a reduction in cement content without compromising strength. In contrast, replacement of fine aggregates with bottom ash in concrete has generally shown a decrease in compressive, flexural, and tensile strengths. The simultaneous replacement of fine aggregates with bottom ash and cement with fly ash resulted in reduced early-age mechanical strength of concrete.

[0007] Natural aggregates meeting the physical and durability requirements are in short supply in certain regions, such as the Wyoming Basin. To overcome the limited supply of aggregates from natural mineral resources, the use of recycled aggregates has increased in recent years. According to the Federal Highway Administration (FHWA), 60 million tons of reclaimed materials have been reused or recycled directly into pavements. At least 41 states recycle concrete for paving applications and 38 states recycle concrete for an aggregate base.

[0008] In addition to the inconsistency observed in the performance of LWAs in concrete, cement production may be harmful to the environment. The process of manufacturing LWAs involves sintering at high temperatures (800°C - 1200°C), which entails high energy consumption and carbon emissions. Carbon dioxide emissions from cement production contribute to approximately 8-10% of global CO2 emissions. A significant portion of these emissions come from the production of standard aggregate materials. As a result, there is growing interest not only in the development of more consistent and cost- 8781485 3Attorney Docket No.: UWYO / 0131PCeffective lightweight aggregates, but also in alternative low-energy production techniques such as cold bonding, alkali activation, and accelerated carbonation.

[0009] Therefore, there is a need for improved aggregates and methods of fabricating aggregates for use in applications such as cement production.SUMMARY

[0010] In one embodiment, a composition is disclosed. The composition includes PC, cementitious materials, superplasticizers, water, silica fume (SF), and one or more additives.

[0011] In another embodiment, a method of forming a composition is disclosed. The method of forming the composition includes mixing a superplasticizer with water to form a wet mixture, mixing additives, silica fume, and PC to form a dry mixture, mixing the wet mixture and the dry mixture to form a PC mixture, curing the PC mixture to form a PC block (PCB), and crushing the PCB to form a PCA.

[0012] In yet another embodiment, a method of forming a pyrolysis char aggregate (PCA) cement is disclosed. The method of forming a PCA concrete includes mixing an air entraining agent, a water reducer, and water to form a solution, mixing a fine PCA, a course PCA, a cementitious material, water, and the solution to form a PCA concrete, and curing the PCA concrete to form a PCA concrete specimen.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.8781485 4Attorney Docket No.: UWYO / 0131PC

[0014] Figure 1 illustrates a flow chart of a method of forming a pyrolysis char aggregate (PCA), according to embodiments described herein.

[0015] Figure 2 illustrates a flow chart of a method of forming a PCA concrete specimen, according to embodiments described herein.

[0016] Figure 3 illustrates a graph of the expansion results of mortar bar specimens, according to embodiments described herein.

[0017] Figure 4 illustrates a graph of the compressive strength of the concrete specimens, according to embodiments described herein.

[0018] Figure 5 illustrates a graph of the flexural strength of the concrete specimens, according to embodiments described herein.

[0019] Figure 6 illustrates a graph of the splitting tensile strength of the concrete specimens, according to embodiments described herein.

[0020] Figure 7 illustrates a graph of the bulk density of the concrete specimens, according to embodiments described herein.

[0021] Figure 8 illustrates a graph of the modulus of elasticity (MOE) of the concrete specimens, according to embodiments described herein.

[0022] Figure 9 illustrates a graph of the particle size distribution of pyrolysis char (PC) and Type IL cement, according to embodiments described herein.

[0023] Figure 10A illustrates a micrograph of the SEM image of the PC, according to embodiments described herein.

[0024] Figure 10B illustrates a micrograph of the SEM image of the PC a graph of the XRD results of the PC, according to embodiments described herein.

[0025] Figure 11A illustrates a micrograph of the SEM image of the PCA after 28 days of curing, according to embodiments described herein.8781485 5Attorney Docket No.: UWYO / 0131PC

[0026] Figure 11 B illustrates a graph of the XRD results of the PC after 28 days of curing, according to embodiments described herein.

[0027] Figure 12 illustrates a graph of the slump and air content of the OD and SSD concrete specimens, according to embodiments described herein.

[0028] Figure 13 illustrates a graph of the air-dried bulk density of both OD and SSD concrete specimens cured at 28 days, according to embodiments described herein.

[0029] Figure 14 illustrates a graph of the mean compressive strength results for each OD concrete specimens cured at 7, 14, 28, and 56 days, according to embodiments described herein.

[0030] Figure 15 illustrates a graph of the mean compressive strength results for each OD concrete specimens cured at 7, 14, 28, and 56 days, according to embodiments described herein.

[0031] Figure 16 illustrates a graph of the flexural strength of PCA concrete specimens, according to embodiments described herein.

[0032] Figure 17 illustrates a graph of the splitting tensile strength results of OD and SSD concrete specimens at 28 days of curing, according to embodiments described herein.

[0033] Figure 18 illustrates a graph of the 28-day modulus of elasticity (MOE) results of OD and SSD concrete specimens, according to embodiments described herein.

[0034] Figure 19 illustrates a graph of the Poisson’s ratios for the OD and SSD concrete specimens, according to embodiments described herein.

[0035] Figure 20A illustrates a graph of the stress-strain response for SSD-NC-NF concrete specimens, according to embodiments described herein.

[0036] Figure 20B illustrates a graph of the stress-strain response for SSD-CC-NF concrete specimens, according to embodiments described herein.8781485 6Attorney Docket No.: UWYO / 0131PC

[0037] Figure 20C illustrates a graph of the stress-strain response for SSD-NC-CF concrete specimens, according to embodiments described herein.

[0038] Figure 20D illustrates a graph of the stress-strain response for SSD-CC-CF concrete specimens, according to embodiments described herein.

[0039] Figure 21 A illustrates a graph of the relationship between compressive strength and MOE of the SSD-NC-NF concrete specimens, according to embodiments described herein.

[0040] Figure 21 B illustrates a graph of the relationship between compressive strength and MOE of the SSD-CC-NF concrete specimens, according to embodiments described herein.

[0041] Figure 21 C illustrates a graph of the relationship between compressive strength and MOE of the SSD-NC-CF concrete specimens, according to embodiments described herein.

[0042] Figure 21 D illustrates a graph of the relationship between compressive strength and MOE of the SSD-CC-CF concrete specimens, according to embodiments described herein.

[0043] Figure 22A illustrates a micrograph of an SEM image of the SSD-NC-NF cement specimen, according to embodiments described herein.

[0044] Figure 22B illustrates a micrograph of an EDS map of silicon in the SSD-NC-NF cement specimen, according to embodiments described herein.

[0045] Figure 22C illustrates a micrograph of an EDS map of calcium in the SSD-NC-NF cement specimen, according to embodiments described herein.

[0046] Figure 23A illustrates a micrograph of an SEM image of the SSD-CC-NF cement specimen, according to embodiments described herein.

[0047] Figure 23B illustrates a micrograph of an EDS map of silicon in the SSD-CC-NF cement specimen, according to embodiments described herein.8781485 7Attorney Docket No.: UWYO / 0131PC

[0048] Figure 23C illustrates a micrograph of an EDS map of calcium in the SSD-CC-NF cement specimen, according to embodiments described herein.

[0049] Figure 24A illustrates a magnified micrograph of the SEM image of the SSD-NC-NF cement specimen, according to embodiments described herein.

[0050] Figure 24B illustrates a magnified micrograph of the SEM image of the SSD-CC-NF cement specimen, according to embodiments described herein.

[0051] Figure 25A illustrates a graph of the XRD pattern of the saturated SSD-NC-NF40 concrete specimen at 56 days of curing, according to embodiments described herein.

[0052] Figure 25B illustrates a graph of the XRD pattern of the saturated SSD-CC-NF40 concrete specimen at 56 days of curing, according to embodiments described herein.

[0053] Figure 25C illustrates a graph of the XRD pattern of the saturated SSD-NC-CF40 concrete specimen at 56 days of curing, according to embodiments described herein.

[0054] Figure 25D illustrates a graph of the XRD pattern of the saturated SSD-CC-CF40 concrete specimen at 56 days of curing, according to embodiments described herein.

[0055] Figure 26 illustrates a graph of the particle size distribution of the raw materials of the PCA cement specimen, according to embodiments described herein.

[0056] Figure 27 illustrates a graph of the thermogravimetric differential thermal (TG-DT) analysis of the PC, according to embodiments described herein.

[0057] Figure 28A illustrates a micrograph of an SEM image of the porous structure of PC, according to embodiments described herein.8781485 8Attorney Docket No.: UWYO / 0131PC

[0058] Figure 28B illustrates a micrograph of an SEM image of the PC, according to embodiments described herein.

[0059] Figure 28C illustrates a graph of the EDS spectrum of the PC, according to embodiments described herein.

[0060] Figure 28D illustrates the elemental mapping of carbon in the PC, according to embodiments described herein.

[0061] Figure 28E illustrates the elemental mapping of silicon in the PC, according to embodiments described herein.

[0062] Figure 28F illustrates the elemental mapping of oxygen in the PC, according to embodiments described herein.

[0063] Figure 28G illustrates the elemental mapping of calcium in the PC, according to embodiments described herein.

[0064] Figure 29 illustrates a graph of the XRD of the raw materials in the cement specimens, according to embodiments described herein.

[0065] Figure 30 illustrates a graph of the unconfined compressive strength (UCS) and bulk density of the concrete specimens, according to embodiments described herein.

[0066] Figure 31 A illustrates a graph of the relationship between the density and compressive strength of the concrete specimens, according to embodiments described herein.

[0067] Figure 31 B illustrates a graph of the relationship between the water absorption and the density of the concrete specimens, according to embodiments described herein.

[0068] Figure 32 illustrates a graph of the water absorption of PCA over time. The PC coarse aggregates were tested under vacuum and ambient conditions, according to embodiments described herein.8781485 9Attorney Docket No.: UWYO / 0131PC

[0069] Figure 33 illustrates a graph of the x-ray diffraction (XRD) for PCA at different curing ages, according to embodiments described herein.

[0070] Figure 34A illustrates a micrograph of a SEM image of the PCA at 3 days, according to embodiments described herein.

[0071] Figure 34B illustrates a magnified micrograph of the SEM image of the PCA at 3 days of curing, according to embodiments described herein.

[0072] Figure 34C illustrates a graph of the EDS spectrum of the PCA at 3 days of curing, according to embodiments described herein.

[0073] Figure 35A illustrates a micrograph of a SEM image of the PCA at 28 days of curing, according to embodiments described herein.

[0074] Figure 35B illustrates a magnified micrograph of the SEM image of the PCA at 28 days of curing, according to embodiments described herein.

[0075] Figure 35C illustrates a graph of the EDS spectrum of the PCA at 28 days of curing, according to embodiments described herein.

[0076] Figure 36 illustrates a graph of the TG-DT curves for PCA after 7 days and 28 days of curing, according to embodiments described herein.

[0077] Figure 37A illustrates a micrograph of an SEM image for the PCA mortar, according to embodiments described herein.

[0078] Figure 37B illustrates a micrograph of an SEM image for the Lummis aggregate mortar, according to embodiments described herein.

[0079] Figure 38 illustrates a graph of the expansion results for mortar bar samples immersed in NaOH solution for 28 days, according to embodiments described herein.

[0080] Figure 39 illustrates a graph of the of the relationship between expansion and UCS of mortars, according to embodiments described herein.8781485 10Attorney Docket No.: UWYO / 0131PC

[0081] Figure 40A illustrates a micrograph of a SEM image of the PCA mortar, according to embodiments described herein.

[0082] Figure 40B illustrates a graph of the EDS spectrum of the PCA mortar, according to embodiments described herein.

[0083] Figure 40C illustrates a micrograph of the elemental mapping of carbon in the PCA mortar, according to embodiments described herein.

[0084] Figure 40D illustrates a micrograph of the elemental mapping of sodium in the PCA mortar, according to embodiments described herein.

[0085] Figure 40E illustrates a micrograph of the elemental mapping of aluminum in the PCA mortar, according to embodiments described herein.

[0086] Figure 40F illustrates a micrograph of the elemental mapping of silicon in the PCA mortar, according to embodiments described herein.

[0087] Figure 40G illustrates a micrograph of the elemental mapping of potassium in the PCA mortar, according to embodiments described herein.

[0088] Figure 40H illustrates a micrograph of the elemental mapping of calcium in the PCA mortar, according to embodiments described herein.

[0089] Figure 41A illustrates a micrograph of a SEM image of the Lummis mortar, according to embodiments described herein.

[0090] Figure 41 B illustrates a graph of the EDS spectrum of the Lummis mortar, according to embodiments described herein.

[0091] Figure 41 C illustrates a micrograph of the elemental mapping of carbon in the Lummis mortar, according to embodiments described herein.

[0092] Figure 41 D illustrates a micrograph of the elemental mapping of sodium in the Lummis mortar, according to embodiments described herein.

[0093] Figure 41 E illustrates a micrograph of the elemental mapping of aluminum in the Lummis mortar, according to embodiments described herein.8781485 11Attorney Docket No.: UWYO / 0131PC

[0094] Figure 41 F illustrates a micrograph of the elemental mapping of silicon in the Lummis mortar, according to embodiments described herein.

[0095] Figure 41 G illustrates a micrograph of the elemental mapping of potassium in the Lummis mortar, according to embodiments described herein.

[0096] Figure 41 H illustrates a micrograph of the elemental mapping of calcium in the Lummis mortar, according to embodiments described herein.

[0097] Figure 42 illustrates a graph of the average expansion results of the concrete prism specimens, according to embodiments described herein.

[0098] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0099] Embodiments of the present disclosure generally relate to a pyrolysis char aggregate. More particularly, the present disclosure relates to a concrete specimen utilizing a pyrolysis char aggregate and methods of making a pyrolysis char aggregate (PCA).

[0100] The inventors have found new and improved methods for fabricating aggregates from coal-derived pyrolysis char (PC). PC is the lightweight, porous byproduct generated through a thermochemical process of pyrolysis, where coal is subjected to high temperatures in the absence of oxygen. A thermochemical process converts mined coals to functional carbon elements through a pyrolysis process. The pyrolysis process is performed at temperatures greater than about 800°C, such as about 1,562°F (850°C) to form PC, which contains at least 80% fixed carbon, about 16% ash, and near zero volatile matter. The PC is utilized to create and manufacture aggregates in concrete, offering an alternative for construction materials. While coal combustion would typically release a significant amount of carbon in the8781485 12Attorney Docket No.: UWYO / 0131PCatmosphere as CO2, pyrolysis leaves most of the carbon in solid residue as PC, minimizing CO2 emissions.

[0101] Embodiments of the present disclosure pertain to the properties, mechanical performance, microstructure, and mineralogical properties of PCA concrete as an alternative structural LWA, and the influence of both coarse and fine PCA in two moisture states: oven-dried (OD) and saturated surface-dry (SSD), on concrete performance. SSD concrete specimens have been further explored in three different water-to-cement (w / c) ratios. Four different aggregate combinations for each w / c ratio have been examined for key properties, including workability, air content, compressive, tensile, and flexural strength, stiffness, and microstructural evolution through XRD and SEM. The desire for environmentally-friendly materials, energy savings, and reduced energy consumption in aggregate materials are enabled by the aggregate materials described herein. The present disclosure demonstrates the viability of PCA in structural concrete, offering a sustainable alternative that reduces reliance on natural aggregates, while valorizing underutilized PC.

[0102] The use of headings is for purposes of convenience and does not limit the scope of the present disclosure. Embodiments described herein can be combined with other embodiments.

[0103] As used herein, “composition” can include component(s) of the composition, reaction product(s) of two or more components of the composition, a remainder balance of remaining starting component(s), or combinations thereof. Compositions of the present disclosure can be prepared by suitable mixing process, combination processes, or reaction processes.COMPOSITIONS:

[0104] A composition (e.g., a pyrolysis char aggregate (PCA)) includes pyrolysis char (PC), cementitious materials, superplasticizers, water, silica fume, and one or more additives. The composition includes about 25% to about 35% PC, about 50% to about 60% cementitious materials, about 5% to about 10% additives, about 2.5% to about 7.5% silica fume, about 0.5% to about 2.5%8781485 13Attorney Docket No.: UWYO / 0131PCsuperplasticizer. The PCA has an expansion of less than 0.10% at 14 days under NaOH immersion. The PCA has a water absorption of about 20% to about 30%, such as about 22% to about 26% in 24 hours. The specific gravity value of PCA is about 1.3 to about 1.4, such as about 1.32 to about 1.38, indicating that the PCAs are relatively light compared to natural aggregates. The percentage of friable particles for coarse PCA is less than about 0.5%, while the percentage of friable particles for fine PCA is less than about 1 %, both within the limits (3.5% for coarse PCA and 1% for fine PCA) specified in Standard Specifications for Road and Bridge Construction by WYDOT (2021 ).

[0105] The PC is derived from coal materials. In one embodiment, the coal materials are produced from the Powder River Basin (PRB) coal, which is classified as sub-bituminous coal. It is contemplated that coal materials from other coal deposits may also be utilized according to the embodiments described herein. In some embodiments, the PC is chemically processed from the PRB coal. Despite having a low thermal content, PRB coal has a low sulfur content and high carbon content. The PC is formed by pyrolizing the coal material in a furnace up to a temperature of about 850°C to remove volatiles and tar.

[0106] The additives may include trass, trass lime, alkaline activators, fly ash, air entraining (AE) agents, algae, graphene oxide (GO), a water reducer, or combinations therein. The AE agents may include natural wood resins, fatty / resinous acids, sulfonated hydrocarbons, and / or synthetic detergents / alkali salts. In some embodiments, the AE agent is a sodium salt, such as an alkene / alkane hydroxy sulfonic acid. In some embodiments, the AE agent includes a potassium hydroxide. The water reducer includes a liquid admixture of one or more of sodium nitrate, sodium thiocyanate, triethanolamine (2,2’,2”-nitrilotriethanol), melamine-based materials, lignosulfates, polycarboxylate ethers (PCEs), naphthalene-based materials, or a combination thereof.

[0107] The superplasticizer may include polycarboxylic ether polymer (such as BASF Melflux), a polycarboxylate ether, a sulfonated naphthalene8781485 14Attorney Docket No.: UWYO / 0131PCformaldehyde, a sulfonated melamine formaldehyde, a lignosulfate, an acrylic polymer, or combinations thereof.

[0108] Silica fume includes an amorphous micronized grey silicon dioxide pozzolan, a densified SF (e.g., Trinic R-E-D 105WS, Trinic R-E-D 106 pm, Trinic Pozz Plus, Trinic Z3-95, DMI NanoPozz 100-D), or an undensified SF (e.g., Riteks microfume 106 pm).

[0109] The cementitious materials may include ordinary Portland Cement (Type I, Type II, Type III, Type IV, Type V), slag cement, slag-modified Portland cement, expansive cement, white cement, water-repellant cement, masonry cement Type N or Type S, cement lime, Type S, Mortar cement, oil well cement, plastic cement, rapid setting cement, Portland blast-furnace slag cement, Portland-pozzolans cement, and pozzolans-modified Portland cement, or combinations thereof. Other types of cement are also contemplated. In some embodiments, the cementitious materials may include ground granulated blast furnace slag (GGBFS), fly ash (e.g., Class C fly ash), ground limestone, and combinations thereof. The ordinary Portland Cement Type II is defined using ASTM C150 / C150M (ASTM 2022). The specific gravity of the cementitious material is about 3.15, in accordance with ASTM C188.

[0110] Figure 1 illustrates a flow chart of a method 100 of forming a pyrolysis char aggregate (PCA). At operation 102, the superplasticizer is mixed with water to form a wet mixture. The superplasticizer and the water are mixed for about 90 second to about 150 seconds, although other durations are contemplated.

[0111] At operation 104, the additives, PC, and silica fume are mixed to form a dry mixture. The additives, PC, and silica fume are mixed for about 150 seconds to about 210 seconds, although other durations are contemplated.

[0112] At operation 106, the wet mixture and dry mixture are mixed to form a pyrolysis char (PC) mixture. The wet mixture and dry mixture are mixed for about 150 seconds to about 210 seconds, although other durations are contemplated.8781485 15Attorney Docket No.: UWYO / 0131PC

[0113] At operation 108, the PC mixture is poured into a mold. The PC mixture is packed, compacted, and compressed into the mold. The PC mixture is compressed using a hydraulic press at about 10 US tons to about 15 US tons.

[0114] At operation 110, the PC mixture is sealed to retain moisture. The PC mixture is sealed to retain moisture for about 20 hours to about 28 hours.

[0115] At operation 112, the PC mixture is cured to form a pyrolysis char block (PCB). The PC mixture is cured in a wet room at a humidity of between about 90% and about 95% for about 24 days to about 32 days.

[0116] At operation 114, the PCB is crushed to form pyrolysis char aggregates (PCA). The PCA is sieved to determine a particle size distribution. Aggregates retained on the No. 4 sieve were classified as coarse PCA, while those that passed through the No. 4 sieve are classified as fine PCA.

[0117] Figure 2 illustrates a flow chart of a method 200 of forming a PCA concrete specimen. At operation 202, an air entraining (AE) agent, a water reducer, and water are mixed to form a solution.

[0118] At operation 204, fine PCA, coarse PCA, cementitious materials, water, and the solution are mixed to form a PCA concrete. The amount of water used to make the solution is included in the total amount of water in the PCA concrete. The PCA concrete is mixed in a mixer for 1 minute to about 5 minutes, such as about 2 minutes to about 4 minutes.

[0119] At operation 206, the PCA concrete is poured into a mold. The mold may include a concrete cylinder mold and a concrete beam mold. The PCA concrete may be poured in two layers, a tamping rod is used to tamp the PCA concrete into the mold, and the outside of the mold was tapped with a mallet hammer to ensure the PCA concrete is poured into the mold uniformly.

[0120] At operation 208, the PCA concrete is cured to form a PCA concrete specimen. The PCA concrete is covered with waterproof plastic for initial curing. The PCA concrete specimens were removed from the molds after 20 to about 28 hours of curing and transferred to a wet room for continuous curing.8781485 16Attorney Docket No.: UWYO / 0131PC

[0121] The PCA concrete specimen has an unconfined compressive strength of about 25 MPa to about 45 MPa. The PCA concrete specimen has a flexural strength of about 3 MPa to about 5 MPa. The PCA concrete specimen has a tensile strength of about 2 MPa to about 4 MPa. The PCA concrete specimen has a bulk density of about 1500 kg / m3to about 2500 kg / m3The PCA concrete specimen has a modulus of elasticity of about 10 GPa to about 40 GPa.EXAMPLES:Test Methods

[0122] The particle size distribution is determined using ASTM C136. PCA was characterized through proximate analysis following the ASTM D7582. The particle size distribution of the Type IL cement and PCA used in this disclosure was determined using a laser diffraction method with a particle size and a Malvern Mastersizer 2000 analyzer.

[0123] The Los Angeles (LA) abrasion test or loss value is conducted according to ASTM C535. In experiment 3, the LA abrasion test was conducted using ASTM C131. The LA abrasion assists in determining the relative quality, toughness, and durability of the aggregates subjected to impact and abrasion.

[0124] The alkali-silica reaction (ASR) test is conducted following ASTM C1260.

[0125] The concrete mix proportions were selected and adjusted according to ACI 211 -22. The bulk density of the PCA was determined using ASTM C29.

[0126] The coarse aggregates are considered to have reached saturated surface dried (SSD) condition when all visible films of water are removed from the surface, according to ASTM C127. The fine aggregates were tested for their surface moisture following the procedure of ASTM C128. A mold having an inside diameter of 40 mm at the top and 90 mm at the bottom is filled with fine aggregates and lightly tamped with a tamper, approximately 5 mm above the top surface of fine aggregate. The mold is then lifted vertically up. If the fine 8781485 17Attorney Docket No.: UWYO / 0131PCaggregate retains the molded shape, surface moisture is present, and if slight slumping occurs, it has reached SSD condition.

[0127] The concrete specimens, unless otherwise noted, are prepared according to ASTM C192.

[0128] The slump of the concrete is measured according to ASTM C143.

[0129] The air content was measured according to ASTM C173.

[0130] The continuous curing of the concrete specimens is performed according to ASTM C511.

[0131] The unconfined compressive strength (UCS) of 51 x 102 mm cylindrical samples for different concrete specimens were measured according to ASTM C39. Axial stress-strain curves for the cylinder specimens were generated using servo-controlled equipment (GCTS RTR-1500), with axial and radial linear variable displacement transformers (LVDT) measuring the strains following the ASTM C39. Three samples for each concrete mix were tested at 7, 14, and 28 days of curing. The loading was applied continuously until the specimen failed, and the maximum axial stress at failure was recorded as the UCS. The minimum desired UCS, as per the concrete mix design, is 34.5 MPa. In experiment 3, the UCS was measured according to ASTM C67.

[0132] The flexural strengths of 102 x 102 x 355 mm concrete beams were measured at 14 days and 28 days of curing using the third point loading method according to the ASTM C78. The concrete beam is supported on each end and loaded on its third point until failure. The modulus of rupture is then calculated as the flexural strength.

[0133] The splitting tensile strength test on the 51 x 102 mm concrete cylindrical specimens was carried out following the ASTM C496. Static modulus of elasticity and Poisson’s ratio of the samples were determined following the ASTM C469.8781485 18Attorney Docket No.: UWYO / 0131PC

[0134] The modulus of elasticity (MOE) of the concrete specimens is measured at 28 days of curing according to the ASTM C496. The axial and longitudinal strains were measured on 51 x 102 mm cylindrical samples using a set of axial and radial extensometers.

[0135] Type IL ordinary Portland cement conforms to ASTM C595 and ASTM C465 and is manufactured by Mountain Cement Company, Laramie, Wyoming. Natural coarse aggregates (NC, granite) and fine aggregates (NF, Lummis sand) are obtained from Croel Inc., a ready-mix concrete supplier in Laramie, Wyoming. Both NC and NF follow the grading requirements for natural coarse and fine aggregates as per ASTM C33.

[0136] The specific surface area of PC is determined using the Brunauer-Emmett-Teller (BET) method with a Micromeritics Gemini VII 2390 surface area analyzer. The true density of PC was assessed via a helium pycnometer.

[0137] Mid-range water reducer-MasterPolyheed 997, meeting the requirements of the ASTM C494, and air entraining admixture-MasterAir AE200, meeting the requirements of the ASTM C260, both provided by Masters Builders Solutions, were used in concrete mix designs.

[0138] Mixing, molding, and curing of concrete specimens were carried out in accordance with the ASTM C192. Air content and slump of the concrete specimens were measured according to the ASTM C173 and ASTM C143, respectively.

[0139] Furthermore, the mineralogical composition of selected concrete specimens was studied by conducting XRD using a Rigaku Smartlab diffractometer with a CuKa radiation source, operated at 40 kV and 40 mA with an angle of reflection, 2θ, varied between 10° and 90°.

[0140] SEM imaging and EDS analysis in experiment 2 were conducted on polished, epoxy-impregnated thin sections using a dual-beam FIB-SEM (ThermoFisher Scientific Helios 5 UX) equipped with an energy dispersive X-ray spectrometer. SEM imaging and EDS analysis in experiment 3 were performed using Hitachi 3700 C SEM.8781485 19Attorney Docket No.: UWYO / 0131PC

[0141] Thermogravimetric / differential analysis (TGA / DTA) was conducted on crushed aggregate using a TA instrument Q500. During the TGA / DTA, the temperature was increased from room temperature to 900°C with a ramp rate of 10°C / min and an inert gas (argon) environment with a flow rate of 50 mL / min.

[0142] Specific gravity and water absorption of the coarse and fine PCA were determined using ASTM C127 and ASTM 128, respectively.EXPERIMENTALExperiment 1:

[0143] Table 1 is a summary of the mixing proportions of ingredients for the pyrolysis char blocks (PCBs). The water to binder ratio of the PCBs is about 0.35. To manufacture PCA, char-based blocks (PCBs) of about 190 x 90 x 55 mm were prepared. The PCBs were cured for 28 days and crushed with a jaw crusher to make aggregates of different sizes. The PCBs have a compressive strength of about 50 MPa to about 60 MPa after 28 days of curing.Table 1. Mixing Proportions of Ingredients for Pyrolysis Char Blocks Ingredient Percentage by Mass (%)PC 30%Cement 55.6%Trass Lime (TL) 7.9%Silica Fume 5.3%Super Plasticizer (SP) 1.2%

[0144] Table 2 is a summary of the engineering properties of the coarse PCA and the fine PCA. The PCA has a higher water absorption than natural aggregates. The coarse PCA has a water absorption of 24.7% in 24 hours, while the fine PCA has a water absorption of 23% during the same period. The specific gravity values are 1.38 for coarse PCA and 1.32 for fine aggregates, indicating that the PCAs are relatively light compared to natural aggregates. The percentage of friable particles 0.45% for coarse PCA and 1.00 for fine PCA,8781485 20Attorney Docket No.: UWYO / 0131PCboth within the limits (3.5% for coarse PCA and 1% for fine PCA) specified in Standard Specifications for Road and Bridge Construction WYDOT (2021 ).Table 2. Engineering Properties of Coarse and Fine Pyrolysis Char Aggregates Property Coarse PCA Fine PCA Water Absorption (24 hours) 24.7% 23%Specific Gravity (oven dried) 1.38 1.32Particle Density (kg / m3) 1371.58 1316.51 Dry-Rodded Bulk Density (kg / m3) 850 810LA Loss Value 24.2% - Friable Particles 0.45% 1.07%Passing No. 200 Sieve 0.56% 1.00%

[0145] Table 3 is a summary of the mixing proportions of the mortar specimens. The fine PCA were subjected to an alkali-sil ica reaction (ASR) test and were compared against reactive and non-reactive natural sands. The aggregate types include fine PCA (MC1) and natural fine aggregates: ML1, MN1, MG1, and MP1. The mortar specimens were 25 mm x 25 mm x 285 mm bars.Table 3. Summary of the Mixing Proportions of Mortar Specimens.Ingredient MCI ML1 MN1 MG1 MP1 Source PC Lummis Pit Collins Pit Granite Canyon Pea Gravel Cement (g) 440 440 440 440 440 Aggregate (g) 492 990 990 990 990 Water 319 206 206 206 206 W / C ratio 0.72 0.47 0.47 0.47 0.47

[0146] Figure 3 illustrates a graph of the expansion results of the mortar bar specimens. Three mortar specimens were prepared for each aggregate type and submerged in NaOH solution at 80°C for about 28 days. The expansion of the mortar specimens was measured after 3, 7, 10, 14, 21, and 28 days. An expansion of less than 0.10% at 14 days under NaOH immersion indicates innocuous behavior, while expansions greater than 0.20% indicate potentially 8781485 21Attorney Docket No.: UWYO / 0131PCdeleterious expansion. Mortar specimens with expansions between 0.10% and 0.20% have marginal behavior, including innocuous and deleterious aggregates. Mortar specimens with PCA (e.g., MC1 ) had the lowest expansion, e.g., about 0.06%, at 14 days among the five mortar bar specimens. The reactive Lummis fine aggregate (ML1) had the highest expansion at 14 days of about 0.26%, while the nonreactive sand from Collins Pit had an expansion of 0.07% at 14 days.Experiment 2:

[0147] Table 4 is a summary of the engineering properties of natural aggregates. A concrete design mix using Type 1 L cement has a target ultimate compressive strength of 34.5 MPa (5,000 psi). A baseline concrete specimen using natural fine aggregate, natural coarse aggregate, and Type 1 L cement was prepared. The natural coarse aggregate was sourced from Granite Canyon and the natural coarse aggregate is sourced from Lummis Pit. MasterPolyheed 997 and MasterAir AE 200 from Master Builder Solutions were used as water reducing admixture and air-entraining agents. The natural aggregates in the baseline concrete specimen were replaced with PCA for an equivalent volume.Table 4. Engineering Properties of Natural AggregatesProperty Natural Course Natural Fine Aggregates Aggregate Source Granite Canyon Lummis Pit Specific Gravity (Oven Dried) 2.73 2.54Water Absorption (24 hours) 0.8% 0.7%Dry-Rodded Bulk Density (kg / m3) 1729 1652Fineness Modulus - 2.92

[0148] Table 5 is a summary of the concrete specimen compositions. The concrete specimens are made using oven dried (OD) aggregates or saturated surface dried (SSD) aggregates. The concrete specimens include OD natural coarse aggregates and natural fine aggregates (OD-NC-NF), OD coarse PCA8781485 22Attorney Docket No.: UWYO / 0131PCand natural fine aggregates (OD-CC-NF), OD natural coarse aggregates and fine PCA (OD-NC-CF), OD coarse PCA and fine PCA (OD-CC-CF), SSD natural coarse aggregates and natural fine aggregates (SSD-NC-NF), SSD coarse PCA and natural fine aggregates (SSD-CC-NF), SSD natural coarse aggregates and fine PCA (SSD-NC-CF), and SSD coarse PCA and fine PCA (SSD-CC-CF). To prepare the OD aggregates, the aggregates were dried in an oven for 24 hours at 230°F and were cooled down to room temperature before being used in the concrete specimens. To prepare the SSD aggregates, the aggregates are submerged in water at room temperature for 24 hours. After soaking, the surface of the coarse aggregates was dried with a towel and a moving stream of air. The fine aggregates were subjected to a uniform flow of warm air and frequent stirring.Table 5. Summary of Concrete Specimen CompositionsWaterreduce AE 200Cemen FA CA Water W / C Slum Air Mix r (% oft (kg / m3(kg / m3(kg / m3rati conten ID3(% of cement P (kg / m ) ) ) ) o (mm) t (%) cement ))OD- NC- 482 684 892 203 0.42 0.77 0.051 114 4.75 NF OD- CC- 482 684 451 287 0.59 0.77 0.018 102 7 NF OD- NC- 482 356 892 280 0.58 0.77 0.078 108 6.25 CF OD- CC- 482 356 451 364 0.72 0.77 0 114 5 CF SSD-NC- 482 689 899 192 0.4 0.77 0.051 108 6 NF SSD-CO482 689 559 193 0.4 0.77 0.077 102 6.5 NF SSD-NC- 482 437 899 193 0.4 0.77 0.098 101 5 CF SSD-CC- 482 437 559 193 0.4 0.77 0.083 82 5.25CF

[0149] The concrete specimens were prepared according to method 200. The concrete cylinder molds were 51 mm x 102 mm. The concrete beam molds 8781485 23Attorney Docket No.: UWYO / 0131PCwere 102 mm x 102 mm x 355 mm. For the concrete cylinder mold, a 10 mm tamping rod was used to tamp the concrete mix in the concrete cylinder molds 25 times and was tapped from the outside 10 to 15 times with a mallet hammer for each of the two layers. For the concrete beam mold, a 16 mm tamping rod was used to tamp each layer 30 times, and each layer was tapped from the outside of the mold with a mallet hammer 10 to 15 times.

[0150] The concrete specimens were tested for compressive strength at 7, 14, 28, and 56 days. The splitting tensile strength and the modulus of elasticity were measured at 28 days. The flexural strength was measured at 14 days and 28 days.

[0151] Figure 4 illustrates a graph of the compressive strength of the concrete specimens. Table 6 is a summary of the compressive strength of the concrete specimens. The 28-day UCS was highest for the SSD-CC-NF concrete specimen, whereas the OD-CC-NF concrete specimen had the lowest UCS. The SSD aggregates concrete specimens had higher UCS than the OD aggregate concrete specimens, with the exception of the OD-NC-NF concrete specimen having a higher UCS than the SSD-NC-NF concrete specimen. The OD-CC-CF concrete specimen showed the highest UCS of the OD aggregate concrete specimens.Table 6. Summary of the Compressive Strength of the Concrete Specimens Mix ID Unconfined Compressive Strength (MPa)7 Days 14 Days 28 DaysOD-NC-NF 32.6 36.2 37.4OD-CC-NF 28.5 29.2 31.6OD-NC-CF 34.4 36.1 37.0OD-CC-CF 34.3 35.7 38.8SSD-NC-NF 29.2 30.5 35.1SSD-CC-NF 38.3 38.7 44.5SSD-NC-CF 36.3 37.1 38.3SSD-CC-CF 36.7 39.1 42.48781485 24Attorney Docket No.: UWYO / 0131PC

[0152] Figure 5 illustrates a graph of the flexural strength of the concrete specimens. Table 7 is a summary of the flexural strength results of the concrete specimens. The OD-NC-NF concrete specimen has the highest flexural strength, while the SSD-CC-CF had the lowest flexural strength. While PCA concrete specimens did not exhibit higher flexural strength at 28 days than natural aggregate concrete specimens, the flexural strength remained comparable, except for the OD-CC-CF and SSD-CC-CF concrete specimens. The OD-CC-NF concrete specimen showed the highest increase in flexural strength from 14 days to 28 days at 17%, whereas OD-CC-CF showed the least increase in flexural strength of 1%.Table 7. Summary of the Flexural Strength Results of the Concrete Specimens Flexural Strength (MPa)Mix ID14 Days 28 DaysOD-NC-NF 4.4 4.5OD-CC-NF 3.4 4.1OD-NC-CF 3.6 4.3OD-CC-CF 3.4 3.4SSD-NC-NF 3.7 4.4SSD-CC-NF 4.0 4.1SSD-NC-CF 3.9 4.4SSD-CC-CF 3.3 3.3

[0153] Figure 6 illustrates a graph of the splitting tensile strength of the concrete specimens. Table 8 is a summary of the splitting tensile strength results of the concrete specimens. Concrete specimens with coarse PCA or fine PCA had lower tensile strength than concrete specimens with natural coarse and fine aggregates. SSD-NC-CF demonstrated the highest tensile strength among the concrete specimens with PCA, whereas OD-CC-CF demonstrated the lowest tensile strength at 28 days.Table 8. Summary of Splitting Tensile Strength Test ResultsMix ID Tensile Strength (MPa)8781485 25Attorney Docket No.: UWYO / 0131PCOD-NC-NF 3.3OD-CC-NF 2.4OD-NC-CF 2.4OD-CC-CF 2.1SSD-NC-NF 2.9SSD-CC-NF 2.9SSD-NC-CF 3.8SSD-CC-CF 3.7

[0154] Figure 7 illustrates a graph of the bulk density of the concrete specimens. Table 9 is a summary of the bulk density of the concrete specimens. For the OD concrete specimens, the OD-NC-NF concrete specimens had the highest bulk density of 2355 kg / m3, which may indicate that concrete specimens with natural aggregates have a denser matrix. The lowest bulk density of 1769 kg / m3is found in the OD-CC-CF concrete specimen, which may indicate that using PCA significantly reduces the bulk density of the concrete specimen. The SSD concrete specimens show a similar trend to OD concrete specimens, but generally have slightly lower bulk densities. SSD-NC-NF exhibited the highest bulk density, whereas SSD-CC-CF had the lowest bulk density.Table 9. Summary of Bulk Density of Concrete SpecimensMix ID Bulk Density (kg / m3) Percent Change from OD-NC-NF OD-NC-NF 2355 0.00OD-CC-NF 2003 -14.97OD-NC-CF 2098 -10.92OD-CC-CF 1769 25.00SSD-NC-NF 2345 -0.43SSD-CC-NF 2015 -14.47SSD-NC-CF 2126 -9.75SSD-CC-CF 1763 -25.158781485 26Attorney Docket No.: UWYO / 0131PC

[0155] Figure 8 illustrates a graph of the modulus of elasticity (MOE) of the concrete specimens. Table 10 is a summary of the modulus of elasticity of the concrete specimens. The OD-NC-NF concrete specimen showed the highest MOE at 35.8 GPa, which may indicate the highest structural stiffness among the concrete specimens. Among the concrete specimens with PCA, OD-CC-CF exhibited the lowest MOE at 14 GPa, while SSD-NC-NF demonstrated the highest MOE at 25.6 GPa. However, the MOE for PCA concrete specimens was lower than that of the concrete specimens with natural aggregates. This may indicate that for PCA concrete specimens, the SSD condition yielded a higher MOE than the OD condition.8781485 27Attorney Docket No.: UWYO / 0131PCTable 10. Summary of the Modulus of Elasticity of the Concrete Specimens.Mix ID Modulus of Elasticity (GPa)OD-NC-NF 35.8OD-CC-NF 19.42OD-NC-CF 21OD-CC-CF 14SSD-NC-NF 30.9SSD-CC-NF 20.76SSD-NC-CF 25.6SSD-CC-CF 14.9

[0156] In summary, a pyrolysis char aggregate (PCA) is disclosed to address the rising need for alternative construction materials. The PCA utilizes pyrolysis char (PC) from coal in manufacturing PCA for concrete and cementbased composite materials. PCA is fabricated by crushing pyrolysis char blocks (PCBs) produced from mixing PC, cementitious materials, and other additives. The PCA showed minimal expansion in the alkali-silica reaction test, with a maximum expansion of 0.06% after 14 days, indicating its suitability in durable concrete applications. A series of concrete specimens were developed with the performance evaluated against conventional concrete specimens using natural aggregates. The concrete specimens using PCA showed 45% higher unconfined compressive and flexural strengths, while tensile strengths were comparable to those of the concrete specimens utilized natural aggregates. PCA concrete specimens had a maximum compressive strength of 44.5 MPa at 28 days, meeting or exceeding the standard strength requirements for structural applications. The PCA concrete specimens had a lower bulk density, on average, by up to 25% than that of the natural aggregate concrete specimens, thus indicating that the PCA concrete is a more lightweight product than natural aggregate concrete specimens. The PCA concrete exhibited 79% higher water demand and increased air-entrapping capacity. The modulus of elasticity (MOE) decreased in PCA concrete, however, the peak strain and prepeak toughness increased, indicating higher pre-failure energy absorption capacity. XRD and SEM indicated that the enhanced formation of calcium 8781485 28Attorney Docket No.: UWYO / 0131PCsilicate hydrate (CSH) and interfacial transition zone (ITZ) densification occurred, owing to the high internal curing capacity of the PCA concrete.Experiment 2:

[0157] Figure 9 illustrates a graph of the particle size distribution of pyrolysis char (PC) and Type IL cement. Table 11 is a summary of the modulus of elasticity of the concrete specimens. Type IL ordinary Portland cement conforms to ASTM C595 and ASTM C465, and is manufactured by Mountain Cement Company, Laramie, Wyoming. The particle size distribution of the Type IL cement and PCA was determined using a laser diffraction method with a particle size and analyzer. The particle size analysis of the cementitious materials indicates that approximately 100% of the particles pass through a 75 pm sieve, approximately 90% of the particles pass through a 30 pm sieve, and approximately 50% of the particles pass through a 15 pm sieve.Table 11. Composition and Physical Properties of Type IL Cement.Components Mass (%)Portland cement > 90CementLimestone < 15CompositionGypsum > 7Silica, Crystalline quartz < 0.1Properties Test results Test standards pH 12.4Density 3.08 g / cm3 ASTM C188 PhysicalParticle size < 200 pmPropertiesFineness 430 m2 / kg ASTM C204 Initial set time 120 min ASTM C191 Compressive strength 41.9 MPa ASTM C109

[0158] Table 12 is a summary of the physical properties of the natural coarse aggregates (NC, granite) and fine aggregates (NF, Lummis sand). The NC has a specific gravity of 2.73, water absorption of 0.8%, and a dry rodded bulk density of 1729 kg / m3. The NF exhibited a specific gravity of 2.54, a water 8781485 29Attorney Docket No.: UWYO / 0131PCabsorption of 0.7%, a dry rodded bulk density of 1652 kg / m3, and a fineness modulus of 2.92.Table 12. Engineering Properties of Natural Coarse and Fine Aggregates.Properties Coarse aggregates Fine aggregates Specific gravity (OD) 2.73 2.54Water absorption (24 0.8% 0.7%hrs.)Dry Rodded bulk 1729 kg / m31652 kg / m3densityFineness modulus - 2.92

[0159] Figure 10A illustrates a micrograph of the SEM image of the PC. Figure 10B illustrates a micrograph of the SEM image of the PC a graph of the XRD results of the PC. The PCA was synthesized in the laboratory using cold bonding and crushing methods and used as a replacement for natural aggregates. PC obtained from PRB coal in Wyoming was used as the major component of PCA, at 30% by weight. PC is obtained through a combined process of pyrolysis and solvent extraction of PRB coal with a yield rate of 46%. PC was characterized through proximate analysis. The composition of the PC is 79.87% fixed carbon, 15.96% ash, 2.97% moisture, and 1.2% volatile matter. The specific surface area of the PC was measured at 262 m2 / g, indicating a highly porous structure. True density was assessed via a helium pycnometer and found to be 1.89 g / cm3. The particle size analysis of the PC indicates that approximately 100% passes at 850 pm sieve, 99.5% passes at 300 pm sieve, and 61 % passes at 75 pm sieve. The XRD analysis shows sharp peaks at 21 ° and 26.6° and moderate peaks at 50.1° and 60°, which may indicate the presence of crystalline silica. A broad peak around 43° (002) may indicate a disordered graphitic carbon structure. A minor peak at 29.2° may indicate calcite, likely present as an impurity in the ash.

[0160] Figure 11A illustrates a micrograph of the SEM image of the PCA after 28 days of curing. Figure 11 B illustrates a graph of the XRD results of the PC after 28 days of curing. To produce PCA, PC (30% by weight) was mixed 8781485 30Attorney Docket No.: UWYO / 0131PCwith 55.6% cement, 5.3% silica fume (SF), and 7.9% trass lime (TL), and 1.2% superplasticizer at a w / c ratio of 0.35. The mixture was cast into prismatic molds, compacted, and pressed at 7 MPa. After 24-hour moisture retention, the blocks were cured for 28 days at 20°C and 90% relative humidity, then crushed and sieved to obtain the desired aggregate sizes. SF and TL are highly reactive pozzolans that promote short-term and long-term hydration. The interaction of SF and TL with portlandite (CH) leads to the formation of calcium silicate hydrate (CSH) and calcium-alumino-silicate-hydrate (C-A-S-H), which may improve the microstructural integrity of PCA. The PCA includes PC coarse aggregates (CC) and PC fine aggregates (CF). After 28 days of curing, the hydration products CH and CSH are shown deposited on the porous surface of PC, contributing to the densification and strength development of the aggregates.

[0161] CC and CF exhibited dry loose bulk densities of 850 kg / m3and 810 kg / m3, respectively, which are below the ASTM C330 limits of 880 kg / m3for coarse LWA and 1120 kg / m3for fine LWA. The fractions of friable particles were 0.45% (CC) and 1.07% (CF), both well below the ASTM limit of 2%. CC showed 24.7% water absorption in 24 hours, 24.2% LA abrasion loss, and 0.56% passing No. 200, while CF showed 23.0% absorption and 1.0% passing No.200. The OD specific gravity values were reported to be 1.38 for CC and 1.32 for CF. Similarly, SSD specific gravities were found to be 1.71 and 1.64 for CC and CF, respectively. OD condition was achieved by drying the aggregates at 105°C for 24 hours to remove moisture content. Both CC and CF followed the grading requirements for lightweight coarse and fine aggregates in accordance with the ASTM C330.

[0162] Table 13 is a summary of the mix designs for OD PCA concrete specimens. The concrete specimens include a reference mix (OD-NC-NF) using natural coarse aggregates and fine aggregates, OD-CC-NF using PC coarse aggregate and natural fine aggregate, OD-NC-CF using natural coarse aggregate and PC fine aggregate, and OD-CC-CF using PC coarse aggregate and PC fine aggregate. In all concrete specimens, the cementitious material volume was kept constant at 482 kg / m3, and the fine aggregate volume was 8781485 31Attorney Docket No.: UWYO / 0131PCmaintained at 45% of the total aggregate volume across all concrete specimens. The water content was determined to compensate for the higher absorption capacity of PCA, aiming to maintain a target slump of 75 mm to 100 mm (3-4 in) across all concrete specimens. A mid-range water reducer (MRWR) was used at a constant dosage (0.77% of cementitious materials) in all OD concrete specimens. Air-entraining admixture (AE 200) was added at varying dosages (0% to 0.05% by mass of cementitious material) to yield an air content of fresh concrete at 4% to 7%.Table 13. Summary of the Mix Designs for OD PCA Concrete Specimens AECement FA CA Water w / c MRWRMix ID 200(kg / m3) (kg / m3) (kg / m3) (kg / m3) ratio (%)(%) OD-NC- 482 684 892 203 0.42 0.77 0.05 NF OD-CC- 482 684 451 287 0.59 0.77 0.02 NF OD-NC- 482 356 892 280 0.58 0.77 0.02 CF OD-CC- 482 356 451 364 0.76 0.77 0CF

[0163] Table 14 is a summary of the mix designs for SSD concrete specimens. The concrete specimens include SSD-NC-NF45 having natural coarse aggregates and natural fine aggregates with a w / c = 0.45, SSD-NC-NF40 having natural coarse aggregates and natural fine aggregates with a w / c = 0.40, SSD-NC-NF35 having natural coarse aggregates and natural fine aggregates with a w / c = 0.35, SSD-CC-NF45 having PC coarse aggregates and natural fine aggregates with a w / c = 0.45, SSD-CC-NF40 having PC coarse aggregates and natural fine aggregates with a w / c = 0.40, SSD-CC-NF35 having PC coarse aggregates and natural fine aggregates with a w / c = 0.35, SSD-NC-CF45 having natural coarse aggregates and PC fine aggregates with a w / c = 0.45, SSD-NC-CF40 having natural coarse aggregates and PC fine8781485 32Attorney Docket No.: UWYO / 0131PCaggregates with a w / c = 0.40, SSD-NC-CF35 having natural coarse aggregates and PC fine aggregates with a w / c = 0.35, SSD-CC-CF45 having PC coarse aggregates and PC fine aggregates with a w / c = 0.45, SSD-CC-CF40 having PC coarse aggregates and PC fine aggregates with a w / c = 0.40, SSD-CC-CF35 having PC coarse aggregates and PC fine aggregates with a w / c = 0.35. SSD concrete specimens were prepared using aggregates in SSD condition and targeted w / c ratios of 0.35, 0.4, and 0.45. The cementitious material was kept constant at 482 kg / m3Air content was 4% - 7%, whereas MRWR dosage varied from 0% - 1.3% depending on the w / c ratio and aggregate type. Fine aggregate volume was kept constant at 0.45% of the total aggregate volume.8781485 33Attorney Docket No.: UWYO / 0131PCTable 14. Summary of the Mix Designs for SSD PCA Concrete Specimens.Cement FA CA Water w / c MRWR AE 200 Mix ID(kg / m3) (kg / m3) (kg / m3) (kg / m3) ratio (%) (%) SSD-NC- 482 670 880 216 0.45 - 0.06 NF45SSD-NC- 482 689 899 192 0.40 0.90 0.08 NF40SSD-NC- 482 725 937 169 0.35 1.00 0.08 NF35SSD-CC- 482 670 544 216 0.45 - 0.05 NF45SSD-CC- 482 689 559 193 0.40 0.77 0.08 NF40SSD-CC- 482 725 584 169 0.35 1.20 0.11 NF35SSD-NC- 482 427 880 216 0.45 - 0.06 CF45SSD-NC- 482 437 899 193 0.40 0.77 0.10 CF40SSD-NC- 482 465 937 169 0.35 1.30 0.11 CF35SSD-CC- 482 465 584 216 0.45 - 0.08 CF45SSD-CC- 482 437 559 193 0.40 0.77 0.08 CF40SSD-CC- 482 465 584 169 0.35 1.30 0.11 CF35

[0164] Aggregates (OD or SSD), along with cement, water, and admixtures, were mixed in a rotating drum-mixer for 3 minutes, followed by a 3-minute rest and 3 minutes of final mixing. Cylindrical specimens (50 mm diameter by 100 mm height) and beam specimens (100 mm width by 100 mm depth by 355 mm8781485 34Attorney Docket No.: UWYO / 0131PClength) were fabricated for measuring different physical and mechanical properties of hardened concrete at various ages. The prepared specimens were cured in a wet room with a relative humidity of 95 ± 5% and a temperature of 23 ± 2 °C until the designated testing age.

[0165] Unconfined compressive strengths of three replicate cylindrical specimens were measured at 7, 14, 28, and 56 days of curing for each concrete mix. Concrete samples were crushed into a powder form, sieved through a No.200 sieve, and freeze-dried for 72 hours to halt hydration prior to XRD tests.

[0166] Figure 12 illustrates a graph of the slump and air content of the OD and SSD concrete specimens. In OD concrete specimens, the water content was determined to achieve a consistent target slump across the four concrete specimens, thereby maintaining consistency. Similarly, the air content was controlled within the range of 4% to 7% to ensure comparable levels of entrainment. Concrete specimens incorporating PCA exhibited a higher water demand than the concrete specimens with natural aggregates to achieve a similar amount of slump, which may be attributed to the porous microstructure and high surface area of PC. Concrete specimens incorporating both PC coarse and fine aggregates (OD-CC-CF) had 79% more water dosage than the baseline OD-NC-NF to achieve a similar slump. Concrete specimens with only one type of PCA substitution (OD-CC-NF and OD-NC-CF) had nearly 40% more water than OD-NC-NF, indicating a strong water absorptive capacity of PC in the dry state. PC absorption kinetics indicate that over 80% of PC total absorption capacity occurs within the first hour of exposure, thus rendering much of the initial mixing water unavailable for workability.

[0167] In SSD concrete specimens, the incorporation of PCA resulted in a consistent reduction in slump across all w / c ratios. For instance, at a w / c ratio of 0.40, slump values declined progressively from 108 mm in the control mix (SSD-NC-NF40) to 102 mm, 95 mm, and 82 mm in the SSD-CC-NF40, SSD-NC-CF40, and SSD-CC-CF40 concrete specimens, respectively. A similar trend was observed for w / c ratios 0.45 and 0.35, which may indicate that the highly porous microstructure of PC retains residual capillary suction, enabling8781485 35Attorney Docket No.: UWYO / 0131PCpost-mixing absorption of mixing water from the paste matrix even after standardized SSD conditioning. Furthermore, the high specific surface area of PC facilitates greater adsorption of water onto particle surfaces, reducing the amount of free water available to the cement matrix. The reduction in slump indicates that porous LWA might continue to absorb mixing water even under SSD conditions due to the unstable water absorption and desorption kinetics.

[0168] In terms of air entrainment, the OD-CC-CF combination achieved 5% air content without the need of any air-entraining admixture (AEA), demonstrating PC’s ability to entrain and stabilize air. In addition, OD-NC-CF and OD-CC-NF combinations recorded higher air content compared to OD-NC-NF, despite using up to 40 % less air entraining agent. This indicates that an increase in LWA content lowers the workability of fresh mix, given a decrease in the slump and an increase in the air content. This may indicate that the interconnected pore network and surface roughness of PC particles facilitate passive air entrapment during mixing. Dry porous aggregates in a concrete specimen may release air trapped in their pores during water absorption, producing air voids at the surface of aggregates, thus increasing air content. Moreover, in SSD concrete specimens, it is mainly observed that an increase in slump has led to an increase in fresh air content even when a smaller amount of air entraining agent is used. This may be due to an increase in slump, which may lower the paste viscosity and yield stress, reduce energy barriers for bubble formation, and allow easier gas dispersion, ultimately increasing the air content.

[0169] Figure 13 illustrates a graph of the air-dried bulk density of both OD and SSD concrete specimens cured at 28 days. Among the concrete specimens with OD aggregates, OD-NC-NF exhibited the highest density of 2,366 kg / m3. The replacement of NC with CC (OD-CC-NF) reduced the density to 2,010 kg / m3(or « 15% lower), while the replacement of NF with CF (OD-NC-CF) yielded 2,073 kg / m3(or « 12% reduction). Complete replacement in OD-CC-CF concrete specimens resulted in the lowest density of 1,761 kg / m3or 25% reduction. These values place OD-CC-CF concrete specimens below the8781485 36Attorney Docket No.: UWYO / 0131PC1,850 kg / m3threshold for structural lightweight concrete per the ASTM C330, indicating potential for structural applications.

[0170] SSD-NC-NF concrete specimens demonstrated the highest densities (2196 kg / m3to 2381 kg / m3) among their respective w / c ratios. This may be due to the high specific gravities and low porosity of natural aggregates, resulting in a dense, well-packed concrete with minimal air entrapment. SSD-CC-NF concrete specimens showed a reduction of approximately 8% to 14%, while SSD-NC-CF concrete specimens experienced a 7% to 9% reduction. SSD-CC-CF combinations showed the lowest densities (1756 kg / m3to 1798 kg / m3), indicating a reduction of 20-25%. This reduction may be due to a synergistic combination of three factors: lower density of both aggregate phases, complete volumetric replacement, and introduction of additional entrapped air during mixing. Additionally, the rough and porous surfaces of crushed LWAs, such as PC, may induce more shear and localized turbulence during mixing, contributing to the formation of entrapped pores in the concrete specimens, which reduces the density. Moreover, within each concrete specimen combination, increasing the w / c ratio from 0.35 to 0.45 reduced the bulk density. For instance, in SSD-NC-NF concrete specimens, density decreased from 2,381 kg / m3(w / c 0.35) to 2,196 kg / m3(w / c 0.45), or an 8% reduction. Similar reductions are seen in SSD-CC-NF, SSD-NC-CF, and SSD-CC-CF concrete specimens. This may be due to Powers’ gel-space theory, which states that increasing the w / c ratio increases capillary porosity and reduces the gel-space ratio, ultimately lowering the density and strength of hardened cement paste. Across all concrete specimens, SSD concrete specimens generally exhibited higher densities than OD concrete specimens, especially in PCA concrete. This is due to the higher absorption capacity of PC in the OD mix (19.5% in 60 minutes), resulting in the removal of water from the mix, reducing effective paste volume and increasing void content. Prewetting LWAs improves particle packing and reduces entrapped air, leading to higher bulk densities.

[0171] Figure 14 illustrates a graph of the mean compressive strength results for each OD concrete specimens cured at 7, 14, 28, and 56 days. The control mix (OD-NC-NF) exhibited strengths of 37 MPa and 39 MPa at 28 and 8781485 37Attorney Docket No.: UWYO / 0131PC56 days, respectively. A consistent reduction in strength was observed across all ages when the natural aggregates were replaced with PC. At 28 days, OD-CC-NF, OD-NC-CF, and OD-CC-CF achieved strengths of 32 MPa, 35 MPa, and 36 MPa, corresponding to reductions of 13.5%, 5.4%, and 2.7% compared to OD-NC-NF. At 56 days, the respective reductions were 10.3%, 7.7%, and 5.1%. This reduction may be attributed to the high porosity and water absorption capacity of dry PC during mixing. The early age extraction of water by dry PC may reduce the effective w / c ratio, resulting in moisture deficit and hindrance in early cement hydration, ultimately lowering the strength. This absorption leads to underhydrated zones and elevated pore volume, particularly affecting strength development at early ages. Though oven-dried LWA initially absorbs pore solution from the cement paste, a portion of the water is eventually released back into the paste, facilitating cement hydration through internal curing, which may be demonstrated by the reduced strength at 7 days for all PCA-based concrete specimens and the recovering compressive strength at 56 days for OD-NC-CF and OD-CC-CF concrete specimens. The comparatively higher long-term strengths achieved in concrete specimens with CF may be attributed to the role of PC particles as a heterogeneous nucleation site for hydration products. The rough surface texture and porous internal structure of PC facilitates the precipitation and retention of CSH within its voids, promoting a more refined microstructure overtime.

[0172] Figure 15 illustrates a graph of the mean compressive strength results for each OD concrete specimens cured at 7, 14, 28, and 56 days. A general decrease in strength was observed as the w / c ratios increased in all combinations, which may be attributed to increased porosity and reduced binder packing. The replacement of natural aggregates with PCA in all the SSD concrete specimens exhibited equal or higher compressive strength for all w / c ratios, especially at 28 and 56 days. The control concrete specimens, SSD-NC-NF35, SSD-NC-NF40 and SSD-NC-NF45, attained 28-day compressive strengths of 40 MPa, 37 MPa, and 28 MPa, respectively. For the 0.35 w / c series, all PCA combinations: (SSD-CC-NF35, SSD-NC-CF35, and SSD-CC-CF35) exhibited 33%, 13%, and 35% higher compressive strength than that of8781485 38Attorney Docket No.: UWYO / 0131PCSSD-NC-NF35, respectively. At 0.40 w / c, SSD-CC-NF40 and SSD-CC-CF40 exceeded the compressive strength of SSD-NC-NF40 by 22% and 24%, respectively, while SSD-NC-CF40 showed a modest 3% gain. At w / c = 0.45, SSD-CC-NF45 and SSD-CC-CF45 surpassed SSD-NC-NF45 by 32% and 46%, whereas SSD-NC-CF45 was 4% lower. The pre-saturated porous structure of the PC serves as an internal curing reservoir, gradually releasing stored water into the surrounding cement paste to maintain internal humidity and sustain hydration beyond the initial curing period. The strength increased when both natural fine and natural coarse aggregates were replaced with PC, highlighting the synergetic effect between the two fractions. Finer LWAs are more effective than coarser LWAs in increasing the protected paste volume, as finer LWAs reduce the average distance between paste and internal water sources. When both coarse and fine saturated aggregates are used together, the system benefits from multi-scale internal curing, enabling more uniform and prolonged hydration, especially at later ages. The rough, angular surfaces and porous carbon structure of PC provide heterogeneous nucleation sites for the formation of CSH and CH, densifying the microstructure and strengthening the ITZ. Compared to OD concrete specimens, SSD concrete specimens consistently achieved higher compressive strength than the baseline, confirming that pre-saturation of PC enhances hydration and strength by maintaining high internal relative humidity, refining pore structure, sustaining a moisture environment, and facilitating improved hydration kinetics.

[0173] Both OD-CC-CF and SSD-CC-CF concrete specimens satisfy the ASTM C330 requirements for both compressive strength and density in structural lightweight concrete, consistently exceeding the 28 MPa threshold at 28 days. These PCA-based concrete specimens with 28-day strengths of 27 MPa to 54 MPa are comparable to or higher than those of cold-bonded biochar aggregate concrete systems for a similar density range. In addition, PCA concrete specimens surpass the compressive strength range of widely used LWA concrete systems, such as expanded clay (18 MPa - 38 MPa) or foamed glass aggregates (23MPa - 27 MPa), demonstrating PC’s viability as an alternative in structural applications.8781485 39Attorney Docket No.: UWYO / 0131PC

[0174] Figure 16 illustrates a graph of the flexural strength of PCA concrete specimens. PCA incorporation generally reduced the flexural strength compared to the control, for both OD and SSD concrete specimens. In OD concrete specimens, OD-CC-CF showed the greatest reduction (about 24%), followed by OD-CC-NF with a moderate loss (~11%), and OD-NC-CF with only about 4% reduction. In SSD concrete specimens, enhanced strength recovery was evident in partial replacements - when either coarse (OD-CC-NF) or fine (OD-NC-CF) aggregate was replaced, maintaining values consistently within 0% - 5% of the OD-NC-NF. In contrast, SSD-CC-CF concrete specimens showed consistently lower flexural strength across all w / c ratios, with a reduction of up to 38%, which may indicate that pre-saturation enhances flexural performance only for partial PCA replacements.

[0175] Fracture surface observations illustrate the fracture morphologies of the beam specimens. The fracture surface morphology depends on the relative tensile strengths of the aggregate, mortar, and ITZ: weaker aggregates yield smoother surfaces due to trans-aggregate cracking, while stronger aggregates produce rougher, more tortuous fractures. In the SSD-NC-NF concrete specimens and SSD-NC-CF concrete specimens, the fracture surface appears rough and irregular, following a tortuous path, indicating that the cracks were diverted by the stiffer coarse aggregates towards the ITZ, where the crack propagation occurred. Due to its crack-bridging ability, the stiffer granite coarse aggregates improve the mechanical skeleton, load bearing under flexure, and strength. Smoother fracture planes observed in the SSD-CC-NF and SSD-CC-CF concrete specimens confirmed that cracks propagated through the PCA rather than along the paste-aggregate interface, indicating that lightweight PC has weaker crack bridging ability. This failure mechanism indicates that in PCA-containing concrete specimens, failure is predominantly governed by poor crack resistance and stiffness of the porous PC. The highly porous nature of PC allows for enhanced tensile stress concentration and quicker stress propagation in the pores, preventing it from absorbing much energy. Voids concentrated in the tensile zone facilitate crack initiation and propagation under load, reducing the flexural and tensile strength of the system. For all four8781485 40Attorney Docket No.: UWYO / 0131PCaggregate combinations, increasing the w / c ratio resulted in a gradual reduction in flexural strength, which may be attributed to the formation of additional capillary pores in the paste, reducing matrix cohesion and energy absorption capacity when a bending load is applied.

[0176] The flexural strength retained in concrete specimens with partial replacement of PCA (3.8 MPa - 4.6 MPa) is either comparable to or higher than other LWA concrete systems. For instance, expanded perlite concrete exhibited 28-day flexural strength in the range 2.5 MPa to 4 MPa while cold-bonded artificial aggregates produced from fly ash, GGBFS, and glass powders yielded similar flexural strengths of 3.5 MPA to 4.2 MPa. Similarly, concrete made with expanded glass or expanded clay exhibited flexural strength values between 2 MPa and 4 MPa. These comparisons indicate that the PCA concrete system can provide competitive or superior bending resistance compared to other established LWA concrete systems.

[0177] Figure 17 illustrates a graph of the splitting tensile strength results of OD and SSD concrete specimens at 28 days of curing. In OD concrete specimens, the baseline OD-NC-NF exhibited the highest tensile strength of 3.7 MPa, while concrete specimens incorporating PCA exhibited a reduction in the tensile strength. A decrease of 44.1 %, 36.2%, and 42.2% was observed in OD-CC-NF, OD-NC-CF, and OD-CC-CF, respectively. In SSD concrete specimens, tensile strength decreases for all aggregate combinations as the w / c ratio increases, which may indicate that a higher w / c ratio leads to higher capillary porosity and reduced paste cohesion, rendering the system a lower tensile load transfer capacity. Compared to the SSD-NC-NF baseline, SSD-CC-NF concrete specimens showed reductions (==13-24%), SSD-NC-CF concrete specimens experienced minimal reductions (<7%), and complete replacement with SSD-CC-CF caused the most reductions (=22-37%). Among the PCA-based concrete specimens in both OD and SSD conditions, NC-CF concrete specimens retained the most tensile strength, indicating the role of granite aggregate in providing a strong tensile skeleton that limits crack propagation and prevents tensile cracking. Although CF has much lower stiffness compared to NC aggregates, its SSD condition may delay water 8781485 41Attorney Docket No.: UWYO / 0131PCrelease, preventing autogenous desiccation and early-age shrinkage cracks, which improves tensile strength development. The reduction in strength of all concrete specimens incorporating PCA indicates inherently lower tensile strength of the porous PCA. The tensile strength of organic materials, including coal, graphite, and charcoal, is lower than that of the typical siliceous mineral aggregates.

[0178] Similarly, biochar-based concrete has weak biochar-paste bonding and formation of weak ITZ leads to reduced flexural and tensile strengths. In PCA concrete specimens, the trans-aggregate fracture observed during flexural and tensile cracking suggests that the ITZ and PCA are the primary sites of failure. The addition of biochar in concrete introduces inhomogeneity in stiffness, weakening the interface between the paste and the aggregate. In addition, air voids trapped in the concrete mix due to the porous nature of PC may create stress concentration zones that facilitate crack initiation and reduce energy absorption during loading. Compared to OD concrete specimens, the SSD conditioning moderately improved the tensile resistance across all combinations. The internal curing effect of prewetted LWAs reduced internal cracking that occurs due to early autogenous shrinkage, enhancing the tensile strength.

[0179] PCA concrete systems (CC-CF concrete specimens) meet the ASTM C330 requirements for both density and tensile strength in structural lightweight concrete, consistently exceeding the 2.2 MPa tensile strength threshold at 28 days. Across all PCA mixtures, splitting tensile strength ranged from 2.2 MPa to 4.1 MPa, which aligns with values reported for other LWA concrete systems, including expanded clay (2 MPa - 5 MPa), and cold-bonded fly ash / glass powder aggregate concretes (3.5-4.5 MPa), and sintered fly ash aggregate concretes (2.6 MPa to 4.4 MPa).

[0180] Figure 18 illustrates a graph of the 28-day modulus of elasticity (MOE) results of OD and SSD concrete specimens. For OD concrete specimens, the highest MOE of 33.5 GPa was observed for the OD-NC-NF mix, reflecting the stiffer and denser aggregate-paste system with natural8781485 42Attorney Docket No.: UWYO / 0131PCaggregates. Partial and complete replacement of natural aggregates with PCA resulted in a reduction in MOE. The OD-CC-NF, OD-NC-CF, and OD-CC-CF concrete specimens showed reductions of 28-day MOE by 34%, 36%, and 55%, respectively. Concrete MOE is related to the stiffness of mortar and aggregate phases; thus, the reduction in MOE in all PCA-incorporated concrete specimens indicates that PCA behaves as a less stiff aggregate phase in the system. LWA concrete can reach up to 100 MPa in compressive strength, while the MOE can reduce up to 40% due to the deformability of aggregates. Similarly, recycled aggregates, owing to their porosity, can yield adequate compressive strength but significantly reduce the MOE.

[0181] In the SSD concrete specimens, MOE followed a similar trend. Replacement of natural aggregates with PCA reduced the MOE at all three w / c ratios. SSD-NC-NF concrete specimens exhibited the highest MOE while SSD-CC-CF concrete specimens recorded the lowest. For all combinations, increases in w / c ratio decreased the MOE. A higher w / c ratio increases the internal porosity and reduces the stiffness of the cement-paste system, lowering the ability to resist deformation. When compared with OD counterparts, SSD concrete specimens generally achieved higher MOE at w / c = 0.35, where improvements ranged from 7% (SSD-NC-NF) up to 34% (SSD-NC-CF). At w / c = 0.40, the benefit persisted for SSD-CC-NF (+2%), SSD-NC-CF (+22%), and SSD-CC-CF (+11%), though SSD-NC-NF was slightly lower (-7%) than its OD counterpart. At w / c = 0.45, the MOE values for all concrete specimens converged into a narrower range (13.1 GPa - 25.9 GPa), highlighting that at a higher w / c, the influence of pre-saturated aggregates is negligible because the paste already contains sufficient water to sustain hydration. Internal curing due to pre-wetted LWAs improved MOE at a lower w / c of 0.35 but had a reducing effect at a higher w / c ratio of 0.45. At higher w / c ratios, internal curing is not necessary to prevent self-desiccation and enhance hydration.

[0182] The MOE values obtained for PCA concrete (13 GPa - 26 GPa) are comparable to expanded clay concrete (8.8 GPa - 21 GPa), sintered fly ash concrete (12 GPa - 22 GPa), and cold-bonded biochar aggregate concrete (22-25 GPa). This indicates that, although PCA concretes exhibit reduced stiffness, 8781485 43Attorney Docket No.: UWYO / 0131PCtheir modulus remains comparable to other established structural LWA systems, indicating that PCA is a reliable alternative lightweight aggregate for structural applications.

[0183] Figure 19 illustrates a graph of the Poisson’s ratios for the OD and SSD concrete specimens. In OD concrete specimens, all concrete specimens incorporating PCA, including partial and full replacements, exhibited comparable Poisson’s ratios to that of the OD-NC-NF mix, indicating that PCA replacement had minimal effect on the concrete's lateral deformation behavior under the dry condition. For all the SSD concrete specimens, Poisson’s ratio ranged from 0.17 to 0.21 across all PCA concrete specimens. No systematic relationship was observed between Poisson’s ratio and the w / c ratio. The Poisson’s ratio is largely independent of the w / c ratio, concrete age, and compressive strength. Nevertheless, the observed range for PCA concrete specimens is typical of normal concrete, suggesting that PCA does not significantly alter the lateral deformation characteristics in concrete.

[0184] Figure 20A illustrates a graph of the stress-strain response for SSD-NC-NF concrete specimens. Figure 20B illustrates a graph of the stress-strain response for SSD-CC-NF concrete specimens. Figure 20C illustrates a graph of the stress-strain response for SSD-NC-CF concrete specimens. Figure 20D illustrates a graph of the stress-strain response for SSD-CC-CF concrete specimens. Table 15 is a summary of the existing models for predicting the modulus of elasticity of concrete. These include provisions from the American Concrete Institute (ACI 318-2019), British Standards (BS 8110-1:1997), Canadian Standards Association (CSA A23.3-04), and the Japan Society of Civil Engineers (JSCE 2007). The steep ascending slope, followed by a moderately sloping descent, for SSD-NC-NF concrete specimens indicates the higher stiffness of the mix and its relatively ductile post-failure behavior. The ascending slope became gentler when the w / c ratio increased, suggesting lower concrete stiffness at a higher w / c. In contrast, SSD-CC-NF concrete specimens exhibit a lower ascending slope than SSD-NC-NF concrete specimens, as reflected in their lower MOE values (18 GPa - 23 GPa), with post-peak branches showing abrupt decline, indicating reduced ductility.8781485 44Attorney Docket No.: UWYO / 0131PC

[0185] However, at a higher w / c ratio of 0.45, a higher strain is sustained before final rupture, demonstrating a slightly softened fracture mode compared to other SSD-CC-NF counterparts. The descending branch of the curve becomes steeper when strength increases and flatter when strength decreases. With an increase in the w / c ratio, the deformability of aggregates becomes more influential in governing failure behavior. In the case of the SSD-CC-NF45 concrete specimens, the higher water content reduces the stiffness contrast between the paste and the compliant PC, leading to a slightly more ductile response.

[0186] In SSD-NC-CF concrete specimens, the strain-stress response did not differ significantly from SSD-NC-NF concrete specimens, exhibiting a similar ascending branch steepness and an equally abrupt post-peak decline indicating, despite the change in fine aggregates, that coarse aggregate is the primary driver of stress-strain response and fracture mode. However, the deformability of porous PC does not always guarantee ductility, especially at low w / c ratio concrete specimens, where premature aggregate crushing or interfacial debonding may govern the fracture mechanism. This effect is more pronounced in SSD-CC-CF concrete specimens, where a mild ascending slope is followed by a steep post-peak descent, especially in SSD-CC-CF35 and SSD-CC-CF40. In SSD-CC-CF45, a more ductile response is observed likely due to paste softening and reduced stiffness gradient at high w / c ratio.Table 15. Summary of the Existing Models for Predicting the Modulus of Elasticity of Concrete.Design code Equation for Ecin GPa LimitsACI 318-2019 Ec= 0.043w1.5(f'c)0'5x 10-31440 < w < 2500 kg / m3BS-8110-1 Ec= 1.7(w)2(f'c)1 / 3 x 10“620 < f'c< 60 MPa CSA A23.3-04 Ec= (3.3(f'c)0.5+ 6.9) (2300) 20 < f'c< 40 MPa / f'c\°'5 / W xJSCE (2007)1518 < f'c< 80 MPaEc“ \2° / (2300)8781485 45Attorney Docket No.: UWYO / 0131PCEc= modulus of elasticity (GPa); f'c= compressive strength (MPa); w = density of concrete (kg / m3).

[0187] Table 16 is a summary of peak stress, strain, modulus, and toughness of SSD concrete specimens. The energy absorption capacity (toughness) of the SSD concrete specimens was calculated as the area under the axial stress-strain curve up to 85% of post-peak stress, using numerical integration via the trapezoidal rule. This method enables estimation of concrete’s ability to accumulate strain energy prior to failure. Concrete specimens incorporating PCA exhibited consistently higher toughness values than those of SSD-NC-NF concrete specimens for all w / c ratios. Despite having a more porous and weaker internal structure than natural aggregates, PCA demonstrates higher toughness owing to its higher deformability and strain capacity. The axial strain corresponding to oPeak (sPeak) is significantly higher for PCA incorporating concrete specimens than SSD-NC-NF concrete specimens, indicating enhanced deformability before peak stress. The ratio of strain at 85% of post-peak stress (ess) to £peak was lower for PCA concrete specimens, indicating that toughness is mostly contributed by pre-peak strain capacity rather than the material being able to continue deforming in a ductile manner after reaching the peak stress. This energy dissipation mechanism in PCA incorporated concrete specimens differs from that of normal-weight concrete, where a significant portion may occur after the peak due to more gradual matrix softening. This indicates that the toughness of normal-weight concrete is less than PCA concrete specimens when the strain corresponding to 85% of postpeak stress is considered as a cutoff, sss / speak is highest in SSD-NC-NF (1.18- 1.44), followed by SSD-NC-CF (1.16-1.35), indicating better post-peak deformability or ductility in concrete specimens incorporating natural coarse aggregates. In contrast, SSD-CC-NF and SSD-CC-CF concrete specimens showed lower sss / speak ratios (1.00-1.19), indicating a steeper post-peak branch despite a much higher peak strain. This steeper post-peak branch indicates that energy dissipation is concentrated before peak stress with limited postpeak deformability.8781485 46Attorney Docket No.: UWYO / 0131PC8781485 47Attorney Docket No.: UWYO / 0131PCTable 16. Summary of Peak Stress, Strain, Modulus, and Toughness of SSD Concrete Specimens(Opeak / £peak £85 MOE ToughnessMix Opeak 085 £peak) £85 / £peak x106x106(GPa) (KPa)X1000SSD-NC- 41 1718 34.9 2382 33 69 24 1.39 NF35SSD-NC- 39 2015 33.2 2378 29 64 19 1.18 NF40SSD-NC- 26 1655 22.1 2384 26 44 16 1.44 NF45SSD-CC- 51 2843 43.4 2862 23 84 18 1.01 NF35SSD-CC- 47 3096 40.0 3201 21 85 15 1.03 NF40SSD-CC- 38 2993 32.3 3566 18 89 13 1.19 NF45SSD-NC- 45 2331 38.3 2711 27 78 19 1.16 CF35SSD-NC- 38 1989 32.3 2679 24 70 19 1.35 CF40SSD-NC- 24 1948 20.4 2314 21 44 12 1.19 CF45SSD-CC- 54 4398 45.9 4561 16 138 12 1.04 CF35SSD-CC- 50 4543 42.5 4550 15 120 11 1.00 CF40SSD-CC- 40 4717 34.0 5020 13 134 8 1.06 CF45Opeak — pea k stress; oss = stress at 85% of post peak stress; £peak = strain corresponc ing to Opeak; £85 = strain corresponding to oss; MOE = modulus of elasticity8781485 48Attorney Docket No.: UWYO / 0131PC

[0188] Figure 21 A illustrates a graph of the relationship between compressive strength and MOE of the SSD-NC-NF concrete specimens. Figure 21 B illustrates a graph of the relationship between compressive strength and MOE of the SSD-CC-NF concrete specimens. Figure 21 C illustrates a graph of the relationship between compressive strength and MOE of the SSD-NC-CF concrete specimens. Figure 21 D illustrates a graph of the relationship between compressive strength and MOE of the SSD-CC-CF concrete specimens. The SSD-NC-NF concrete specimens showed the strongest alignment with existing empirical models and an R2of 0.74, indicating predictability for normal-weight concrete. A coefficient of 4.56 and power of 0.49 is shown in Equation (1 ) aligns with the coefficient often varying from 4.0 to 5.5 and the power is close to 0.5, as demonstrated in prior studies.Ecin GPa = 4.92(f'c)0'49(1)

[0189] When NC is replaced with CC, the existing models significantly overestimate the MOE. The lower coefficient of 1.18 indicated in Equation (2) indicates lower stiffness for SSD-CC-NF concrete specimens compared to SSD-NC-NF due to the low modulus, porous PCA. However, a higher coefficient of 0.75 indicates a more sharply increasing modulus with an increase in compressive strength. This may be due to internal curing-induced densification of the ITZ, which reduces the stiffness mismatch between the aggregate and paste phases, thus enhancing stress distribution and overall stiffness gain.Ecin GPa = 1.18(f'c)0.75(2)

[0190] Similarly, for SSD-NC-CF concrete specimens, the existing models overestimated the MOE at lower strength levels. Equation (3) utilizes a lower coefficient of 1.79 and a higher exponent of 0.69, indicating reduced initial stiffness and a steeper stiffness gain at higher compressive strengths, similar to the response of SSD-CC-NF concrete specimens and underscoring the importance of calibrating the modulus-strength relationship when using PCA in concrete specimens.8781485 49Attorney Docket No.: UWYO / 0131PCEcin GPa = 1.78(f'c)0'69(3)

[0191] Unlike other concrete specimens, the observed MOE values for SSD-CC-CF concrete specimens are lower than the predictions from empirical models over the compressive strength range, with no evidence of convergence at higher strengths, as shown in other PCA concrete specimens. It is believed that the combined effect of highly porous and compliant PCA on both scales significantly increases the deformability of the paste-aggregate system, limiting stiffness development regardless of strength gain. The low exponent of 0.37 in Equation (4) indicates that internal curing and matrix densification benefits of PCA are outweighed by the detrimental impact of combined aggregate compliance when used at 100% PCA replacement.Ecin GPa = 3.56(f'c)0,37(4)

[0192] Figure 22A illustrates a micrograph of an SEM image of the SSD-NC-NF cement specimen. Figure 22B illustrates a micrograph of an EDS map of silicon in the SSD-NC-NF cement specimen. Figure 22C illustrates a micrograph of an EDS map of calcium in the SSD-NC-NF cement specimen. In a normal-weight concrete system, the ITZ appears porous, consistent with a well-established “wall effect” that leads to localized bleeding and higher precipitation of portlandite (CH). The ITZ region is predominantly filled with CH, rendering a high calcium element signal in the EDS mapping. This is caused by the high mobility of Ca+2ions from dense cement paste to porous ITZ due to higher concentration gradients in this zone. The EDS maps show a sharp Ca-rich belt at the interface, while Si signals are very mild and diminished, confirming that ITZ is dominated by CH rather than calcium silicate hydrate (CSH). This microstructure, dominated by higher porosity and poor Si enrichment, corresponds to a weaker and wider ITZ, which is responsible for crack initiation and propagation in the ITZ, as observed during failure in NC-NF concrete specimens.

[0193] Figure 23A illustrates a micrograph of an SEM image of the SSD-CC-NF cement specimen. Figure 23B illustrates a micrograph of an EDS map of silicon in the SSD-CC-NF cement specimen. Figure 23C illustrates a 8781485 50Attorney Docket No.: UWYO / 0131PCmicrograph of an EDS map of calcium in the SSD-CC-NF cement specimen. In contrast, CC-NF displays a denser ITZ with minimal voids, as well as a more uniform distribution of PC and Si in the ITZ. Brighter Si signals overlapping with PC are observed at the ITZ and extending into surface-connected pores of aggregates.

[0194] Figure 24A illustrates a magnified micrograph of the SEM image of the SSD-NC-NF cement specimen. Figure 24B illustrates a magnified micrograph of the SEM image of the SSD-CC-NF cement specimen. The abundant surface pores of PC are evident, which act as nucleation sites for hydration products, while the water stored within these pores sustains hydration. This results in the formation of CH and secondary CSH inside the aggregate pores, providing a strong mechanical interlock and physical adhesion. Similar mechanisms have been reported in LWAs like pumice and expanded clay, where higher surface porosity of aggregates reduces the wall effect associated with ITZ formation and initiates the growth of CSH and CH directly from the aggregate surface. The penetration of hydration products into the pores of PC enhances adhesion at the interface and redirects crack propagation into the aggregate body rather than along the boundary, as observed in the failure modes of PCA concrete specimens. Consequently, the strength of normal-weight concrete tends to correspond more closely to that of the cement paste, whereas in lightweight aggregate concretes the overall strength is governed by the intrinsic strength of the aggregates themselves.

[0195] Figure 25A illustrates a graph of the XRD pattern of the saturated SSD-NC-NF40 concrete specimen at 56 days of curing. Figure 25B illustrates a graph of the XRD pattern of the saturated SSD-CC-NF40 concrete specimen at 56 days of curing. Figure 25C illustrates a graph of the XRD pattern of the saturated SSD-NC-CF40 concrete specimen at 56 days of curing. Figure 25D illustrates a graph of the XRD pattern of the saturated SSD-CC-CF40 concrete specimen at 56 days of curing. Among the concrete specimens incorporating natural aggregates, SSD-NC-NF40 and SSD-NC-CF40 exhibit well-defined peaks for crystalline silica (quartz), primarily originating from unreacted natural sand. SSD-CC-NF40 also shows moderate quartz intensity due to partial use 8781485 51Attorney Docket No.: UWYO / 0131PCof natural fines. In contrast, the SSD-CC-CF40 mix demonstrates only a minimal quartz peak, attributed to minor contamination or residuals from silica fume used in the fabrication of the PCA. Across all the PCA-incorporated concrete specimens, the XRD profiles exhibit more prominent peaks centered around 20 = ~29°, indicating an enhanced formation of CSH relative to the SSD-NC-NF baseline. This enhancement in CSH peak reflects the internal curing effects from porous PC, which gradually release stored water, sustain clinker dissolution, and extend cement hydration, leading to high compressive strength. Interestingly, despite the strong CSH development, the alite and belite peaks at 20 = ~33° and ~31.5°, as well as the portlandite peaks, are more intense in the SSD-CC-NF40 and SSD-CC-CF40 concrete specimens than in SSD-NC-NF40 and SSD-NC-CF40 concrete specimens. It is believed that the residual alite, belite, and portlandite crystals carried over from the PCA themselves, as confirmed by the XRD of the aggregates. In the SSD-NC-CF40 concrete specimen, however, the contribution of residual phases from PC fine aggregates is comparatively low, owing to their lower volumetric replacement (~45% of total aggregate), and thus the peaks are less pronounced. Similarly, the calcite peaks are lower in SSD-CC-NF40 and SSD-CC-CF40 compared to SSD-NC-CF40, which may be due to enhanced matrix densification from the internal curing effect of PCA. In SSD-CC-NF40, coarse PCA promotes pore refinement, while in SSD-CC-CF40, the combined use of coarse and fine PCA further limits CO2ingress, reducing carbonation. Carbonation resistance in LWA concrete is primarily controlled by paste permeability rather than the type of aggregate. The biphasic carbonation model indicates that a well-hydrated, dense matrix significantly delays carbonation, reducing calcite formation.

[0196] In summary, the performance of concrete incorporating PCA, synthesized via cold bonding using PC, was determined to be a sustainable alternative to natural aggregates. In particular, the: OD concrete specimens with PCA exhibited higher water demand (up to 79%) and air entrapment capacity than the control mix; SSD concrete specimens with PCA had reduced slump values by up to 24%, reflecting residual internal suction of PC; SSD concrete specimens with PCA achieved up to a 45% gain in compressive8781485 52Attorney Docket No.: UWYO / 0131PCstrength over the control mix; OD concrete specimens demonstrated early age reduction (up to 10%), but strength recovered at later ages; 100% PCA replacement significantly reduced the flexural and tensile strengths, while partial fine aggregate replacement (NC-CF) limited reductions up to 7%; complete PCA replacement reduced the bulk density of concrete by up to 25% (« 1750 kg / m3), meeting ASTM C330 requirements for structural lightweight concrete; partial replacements of PCA yielded densities between 2000 and 2100 kg / m3; peak strain and pre-peak toughness increased with PCA replacement, indicating enhanced pre-peak energy absorption capacity; XRD and SEM analysis revealed enhanced formation of CSH and improved ITZ densification in PCA concrete specimens, owing to the internal curing potential and porous nature of PCA; and PCA formed via a low-energy process demonstrated its viability in structural concrete, offering a sustainable alternative to natural aggregates.Experiment 3:

[0197] The PC utilized in this experiment is substantially similar to the PC utilized in Experiment 2. Due to the high surface area, intrinsic porosity, and low density of PC, PC aggregates (PCA) is a useful candidate for developing LWAs. The absence of reactive amorphous silica in PCA combined with the use of supplementary cementitious materials (SCMs) like trass lime and silica fume, which may bind Ca(OH)2 and reduce pore solution alkalinity, contribute to an aggregate system with enhanced resistance to ASR.

[0198] Figure 26 illustrates a graph of the particle size distribution of the raw materials of the PCA cement specimen. The particle size analysis of received PCA shows that approximately 100% of the particles pass through an 850 pm sieve, approximately 77.5% of the particles pass through a 300 pm sieve, and approximately 35.9% of the particles pass through a 75 pm sieve. For ball milled PC, approximately 100% of the particles pass through the 850 pm sieve, approximately 99.5% of the particles pass through the 300 pm sieve, and approximately 61% of the particles pass through the 75 pm sieve.8781485 53Attorney Docket No.: UWYO / 0131PC

[0199] Figure 27 illustrates a graph of the thermogravimetric differential thermal (TG-DT) analysis of the PC. The TG-DT analysis indicated that approximately 23% of the total weight is not lost until the end of the experiment. Below 200°C, around 9% of the total weight loss is observed with a small peak in the derivative weight loss curve, which may be due to evaporation of moisture that was absorbed by the PC after the pyrolysis process. Minor weight loss is observed in the temperature range between 200°C and 400°C, which may be due to the release of volatile matter in the PC. Large decreases in weight from 600°C and 900°C, along with a peak in the derivative curve at 686°C, can be observed, which may be due to the decomposition of calcium carbonate. During pyrolysis, calcite present in the coal is only partially decomposed to form CaO and CO2 due to short residence time in the rotary kiln and shifting of decomposition temperature of calcite in an inert environment. The remaining calcite and CaO may contribute to the ash content of the PC, as shown in Figure 10B. The XRD pattern shows peaks at 21°, 26.6°, 50.1°, and 60°, suggesting the presence of a crystalline form of silica in the PC. A broad peak at 43°, corresponding to graphitic basal plane (002), indicates the presence of a disordered carbon structure. A peak for calcite is observed at 29.2°, corroborating the findings of TG-DT analysis and SEM.

[0200] Figure 28A illustrates a micrograph of an SEM image of the porous structure of PC. Figure 28B illustrates a micrograph of an SEM image of the PC. Figure 28C illustrates a graph of the EDS spectrum of the PC. Figure 28D illustrates the elemental mapping of carbon in the PC. Figure 28E illustrates the elemental mapping of silicon in the PC. Figure 28F illustrates the elemental mapping of oxygen in the PC. Figure 28G illustrates the elemental mapping of calcium in the PC. The porous structure of PC may be attributed to the decomposition and melting of organic matters during pyrolysis. EDS mapping indicates a strong presence of carbon, approximately 72% by weight. The presence of oxygen may be due to the persistence of stable -OH, C=O, and C=C functional groups even at elevated pyrolysis temperatures, along with the incomplete degradation of oxygen-containing species. Other elements, such8781485 54Attorney Docket No.: UWYO / 0131PCas magnesium, silicon, aluminum, zinc, and calcium contribute less than about 7% of the total weight.

[0201] Figure 29 illustrates a graph of the XRD of the raw materials in the cement specimens. Table 17 is a summary of the x-ray fluorescence (XRF) of the raw materials in the cement specimens. The raw materials include Type l / ll cement, silica fume (SF), and trass lime (TL). The XRD patterns for cement specimens showed peaks at 29.3°, 32.6°, 34.3°, and 41.2°, indicating the presence of crystalline phases of alite (C3S), belite (C2S), tricalcium aluminate (C3A), and tetra calcium aluminoferrite (C4AF). The XRD analysis of silica fume indicates a broad hump at 20 = 21° for amorphous silica. Some sharp peaks are observed on the broad hump of the silica fume, indicating the presence of crystalline phases of quartz and tridymite. Sharp peaks at 26.6°, 36.5°, and 60° indicate the presence of a stable crystalline form of silica. The surface area of SF is about 15 m2 / g to 20 m2 / g with a specific density of about 2.2 to 2.3. The SF has a silica content of over 90% and other minor elements like calcium, aluminum, iron, and sulfur. Trass lime consists of natural hydrated lime and trass powder as a natural pozzolan. The bulk density of 0.6 kg / m3and more than 80% of lime component. XRD patterns for TL indicate peaks of portlandite at 20 = 18.1°, 34.1°, and 47.1°. A minor quartz peak at 26.6° and feldspar reflections near 31° and 39° can be attributed to trass components. Furthermore, the polycarboxylate (PCE) based superplasticizer (SP) was utilized, in particular BASF Melflux 2651 F in light yellowish powder form.Table 17. Summary of the X-Ray Fluorescence of the Raw Materials in the PC.Oxides Concentration (%wt)Cement l / ll Silica Fume Trass LimeCaO 63.3 1.28 82.34SiO219.66 94.32 5.38781485 55Attorney Docket No.: UWYO / 0131PCAI2O3 4.36 0.13 2.9Fe2Os 3.41 0.68 3.51MgO 1.22 0.6 2.54TiO20.16 0.11 0.35SO3 3.62 0.71 0.74K2O 0.81 0.68 ND

[0202] Table 18 is a summary of the specific gravity values of the aggregates used in the accelerated mortar bar test (AMBT). Type IL cement (containing >90% Portland clinker, <15% limestone, and >7% gypsum) supplied by Mountain Cement Company, Laramie, Wyoming was used. The equivalent alkali content of the cement, as per the mill test report, is 0.63 and its bulk density is 3.08 g / cm3. Aggregates from four different sources in Wyoming were supplied by Croel Inc. in Laramie, Wyoming.Table 18. Summary of the Specific Gravity Values of the Aggregates in AMBT. Property PC Lummis Sand Collins Sand Granite Pea Gravel Specific Gravity 1.38 2.54 2.55 2.73 2.64

[0203] Table 19 is a summary of the particle size requirements of the aggregates used in the AMBT. The coarse aggregates, granite and pea gravel, were crushed to get the required size of aggregates.Table 19. Summary of the Particle Size Requirements of the Aggregates in AMBT.Sieve Size Percent (%)Passing Retained4.75 mm 2.36 mm 102.36 mm 1.18 mm 251.18 mm 600 pm 258781485 56Attorney Docket No.: UWYO / 0131PC600 pm 300 pm 25300 pm 150 pm 15

[0204] Table 20 is a summary of the mixing proportions for the concrete specimens used in the AMBT. The mixing proportions and water-cement ratio for AMBT were determined from ASTM 1260 and were 1.12 for PCA-based concrete specimens and 2.25 for all other concrete specimens. A higher water / cement ratio for the mortar bar samples with PCA was used to account for the high water absorption of the PC.8781485 57Attorney Docket No.: UWYO / 0131PCTable 20. Summary of the Mixing Proportions of Concrete Specimens Used in the AMBT.Ingredients Mass (kg / m3)PCA Lummis Collins Granite Pea Sand Sand Gravel Cement 535 593 594 616 605 Aggregate 599 1334 1337 1385 1361 Water 388 278 278 288 283 Water / Cement Ratio 0.72 0.47 0.47 0.47 0.47

[0205] Table 21 is a summary of the mix designs for various building material specimens. Production of pyrolysis char aggregates (PCA) involves i) mixing; ii) preparing PC prismatic blocks; and iii) crushing and screening. To prepare the CB concrete specimens, air dried PC is mixed with cementitious materials, SF, and TL for 3 minutes in a mechanical mixer at about 60 rpm. SP is mixed with water and added to the dry mix, and the wet mixing is performed for 3 minutes. The wet mixture is transferred into prismatic metal molds with dimensions of 190 x 90 x 55 mm. The mixture is filled in the mold in two layers, with each layer being compacted with a tamping rod 20-25 times. The molded concrete specimens are pressed using a hydraulic press at 7 MPa for one minute. The pressed concrete specimens are covered with plastic membranes to retain moisture for 24 hours before demolding. After demolding, the concrete specimens are transferred to a wet room for curing at a constant temperature of 20°C and relative humidity of 90%. After curing for 28 days, the blocks are crushed with a jig crusher to obtain aggregates (PCA). The PCA is screened to obtained PCA of the desired size.8781485 58Attorney Docket No.: UWYO / 0131PCTable 21. Summary of Mix Designs for Various Building Material Specimens. Product ID Percent Weight (wt%) Pressing W / C PC Cement SF TL Binder Pressure Ratio (MPa)Brick HC20- 70 29.4 0 0 0.6 3.5 1.7 03HC20- 70 29.4 0 0 0.6 7.0 1.7 07HC20- 70 29.4 0 0 0.6 10.0 1.7 10Stone SV-53 40 53.5 5.3 0 1.2 7.0 0.5 Veneer SV-70 40 53.5 5.3 0 1.2 7.0 0.7 Cubes G1-0 40 58.8 0 0 1.2 7.0 0.6 G1-1 40 58.8 2.8 0 1.2 7.0 0.6 G1-2 40 53.5 5.3 0 1.2 7.0 0.6 G1-3 40 49 9.8 0 1.2 7.0 0.6 Brick G1-2b 40 53.5 5.3 0 1.2 7.0 0.6 Paving CH30 30 63.5 5.3 0 1.2 7.0 0.3 Block CH30- 30 0 5.3 63.5 1.2 7.0 0.3 TL1CH30- 30 31.8 5.3 31.7 1.2 7.0 0.3 TL2CH30- 30 47.6 5.3 15.9 1.2 7.0 0.3 TL3CH30- 30 55.6 5.3 7.9 1.2 7.0 0.3 TL4PCA C30 30 55.6 5.3 7.9 1.2 7.0 0.3

[0206] After curing for a period of 7 days and 28 days, the CB concrete specimens were weighed and the dimensions were measured using an electronic Vernier caliper for calculating bulk density.8781485 59Attorney Docket No.: UWYO / 0131PC

[0207] Figure 30 illustrates a graph of the unconfined compressive strength (UCS) and bulk density of the concrete specimens. The UCS values of the CB concrete specimens at 7 days and 28 days are 49.4 MPa and 61.2 MPa, respectively, and the air-dried bulk density at 28 days is 1.66 g / cm3In the HC20 brick series, the higher UCS exceeded 10 MPa at 28 days, which may indicate that the incorporation of reactive pozzolans and reduction in PC content may be useful. The G1 series provided the highest UCS while increasing the density. The increase in the UCS may be attributed to the reaction of SF with calcium hydroxide to form calcium silicate hydrate (CSH) as a result of pozzolanic reactions. SF acts at the PC-cement paste interface, where there is a high concentration of calcium hydroxide due to the excess water availability in the PC pores. Therefore, the pores are filled with dense CSH products, improving particle packing, reducing porosity, densifying the structure, and increasing strength.

[0208] The addition of a blend of trass and lime (TL) at 7.9% of the total mixture in the C30 series with a w / c ratio of 0.37 exhibited increased strength and density at 28 days. The addition of TL facilitates the reaction of the pozzolans while being low in CaO. The increase in UCS may be due to the activation of trass by the lime, resulting in the formation of hydration products like CSH and calcium aluminate hydrates (CAH). The pozzolanic reaction between SF and hydrated lime causes CSH to form and grow in the cement paste capillary voids, improving the strength of the cement paste. Furthermore, higher PC content requires more water in the mix due to the porosity and absorbent nature of the PC, which can absorb a significant quantity of water during mixing. The use of superplasticizers (SP) maintains proper consistency and workability in the CB concrete specimens. The SP disperses the cement particles through the mechanism of electrostatic repulsion and steric hindrance, thus reducing flocculation and enhancing fluidity.

[0209] Figure 31 A illustrates a graph of the relationship between the density and compressive strength of the concrete specimens. Figure 31 B illustrates a graph of the relationship between the water absorption and the density of the concrete specimens. A positive correlation (R2=0.73) is shown between density 8781485 60Attorney Docket No.: UWYO / 0131PCand compressive strength, indicating that the PCA bricks and blocks achieve higher UCS. A negative correlation (R2=0.87) is observed between density and water absorption, confirming that the increasing PC content increase the porosity, and thus reduces the density and elevates the water absorption capacity. Concrete specimens with lower PCA content coupled with the higher proportion of pozzolans yield denser matrices associated with improved particle packing and reduced porosity. It is believed the higher proportions of cementitious materials and pozzolans in the mix filling the matrix with denser hydration products, thus increasing the strength and density. In addition, PC has a comparatively lower density compared with other constituents, thus causing the density to increase when the PC content decreases.

[0210] Table 22 is a summary of the physical properties of PCA and other LWAs. The loose bulk density of PC coarse (850 kg / m3) and fine (810 kg / m3) aggregates are below the threshold values for LWAs (880 kg / m3for coarse aggregate and 1120 kg / m3for fine aggregate). Due to the high porosity microstructure of PC, the PCA exhibits 24-hours water absorption values of 24.7% for coarse aggregate and 23.03% for fine aggregates. The water absorption values are comparable to those observed in commercial LWAs, such as expanded clay (12%-26%) or sintered fly ash (10%-33%).Table 22. Summary of the Physical Properties of PCA and other LWAs.Property Coarse Fine Expanded Sintered Expanded PCA PCA Clay Fly Ash Slate Water 24.7 23.030 12-24 24-25 6-9 Absorption(24h, %)Specific 1.38 1.32 0.60-1.01 1.32-1.35 1.45 Gravity(OD)Specific 1.71 1.64Gravity(SSD)8781485 61Attorney Docket No.: UWYO / 0131PCParticle 1371.58 1316.51 600-1092 1320-1340 805-833 Density(kg / m3)Dry Loose 850 810 339-781 720-730BulkDensity(kg / m3)LA Loss 24.2 - - - 25 Value (%)Friable 0.45 1.07Particles(%)Passing No. 0.56 1200 Sieve(%)

[0211] Figure 32 illustrates a graph of the water absorption of PCA over time. The PC coarse aggregates were tested under vacuum and ambient conditions. Over 80% of the total absorption capacity is reached within the first 60 minutes. Under vacuum conditions, the absorption reached approximately 21% after 60 minutes, which is higher than the 19.5% absorption under atmospheric pressure. Therefore, although vacuum saturation is more efficient, atmospheric soaking provides comparable absorption values within the timeframe. The absorption process shows rapid initial uptake within the first 15 minutes, followed by a gradual plateau, indicating a high degree of accessible porosity and permeability in PC. The rapid uptake makes PCA favorable for internal curing applications, promoting sustained hydration in low w / c concretes.

[0212] Specific gravity was measured in both oven dried (OD) and saturated surface dry (SD) conditions, with values of 1.38 (OD) and 1.71 (SSD) for coarse PCA and 1.31 (OD) and 1.64 (SSD) for fine PCA. The difference in specific8781485 62Attorney Docket No.: UWYO / 0131PCgravity between the OD and SSD conditions reflects the porosity and absorption characteristics of the aggregates.

[0213] The LA abrasion value for the coarse PCA is 24.2%. This is comparable to the expanded shale and clay aggregates, whose LA value is typically in the range of 20% to 30%. Furthermore, the PCA displayed minimal friable particles (0.45% for coarse and 1.07% for fine) and fines passing the No.200 sieve (0.56% and 1%, respectively), indicating good structural integrity and cleanliness. The physical and mechanical characteristics establish PCA as a structurally competent, lightweight material with high internal curing capacity and strong abrasion resistance, offering a sustainable alternative to conventional LWAs for high-performance concrete applications.

[0214] Figure 33 illustrates a graph of the x-ray diffraction (XRD) for PCA at different curing ages. The different ages include 15 minutes after mixing, 7 days after curing, and 28 days after curing. The PCA prepared after 15 minutes of mixing was a treated as the baseline for comparing and analyzing the hydration phenomena occurring in the PCA at advanced stages of hydration, i.e., 7 days and 28 days. At 15 minutes, the PCA is in an early stage of hydration, as strong peaks of unreacted cement phases, such as alite (C3S), belite (C2S), and aluminates (C3A, C4AF), are observed. Early precipitation of ettringite is observed from a peak at 15.2° without any substantial evidence of formation of hydration products like CSH and CH. The ettringite peaks have diminished at 7 days and 28 days, which may be due to the conversion of ettringites to monosulfates when hydration progresses and the destabilization of ettringite due to the ongoing pozzolanic reaction. Pozzolans like trass lime and silica fume lead the consumption of portlandite, increasing formation of CSH, reducing alkali concentration and PH of the pore solution and destabilizing ettringite. The increased consumption of portlandite is shown in the reduction of peak intensity at 28 days compared to 7 days. The interaction of portlandite and pozzolans to form extra CSH to enhanced the strength development of PCA. Some peaks for calcite at 39.4° are observed at all ages, indicating the carbonation of free lime (CaO) or calcium carbonate present in the PC ash. Sharp and stable peaks at all ages at 26.7°, corresponding to 8781485 63Attorney Docket No.: UWYO / 0131PCcrystalline silica, are observed. While PC does not explicitly take part in the chemical reactions during cement hydration, the PC facilitates internal curing and promotes the overall hydration process acting as a nucleation site for the formation of hydration products.

[0215] Figure 34A illustrates a micrograph of a SEM image of the PCA at 3 days. Figure 34B illustrates a magnified micrograph of the SEM image of the PCA at 3 days of curing. Figure 34C illustrates a graph of the EDS spectrum of the PCA at 3 days of curing. Figure 35A illustrates a micrograph of a SEM image of the PCA at 28 days of curing. Figure 35B illustrates a magnified micrograph of the SEM image of the PCA at 28 days of curing. Figure 35C illustrates a graph of the EDS spectrum of the PCA at 28 days of curing. The porous interface of the PCA is visible, filled with ettringite needles and hydration products such as CSH and CH at both 3 days and 28 days, resulting in a denser microstructure. The accumulation and precipitation of hydration products in the PC pores, improving microstructural and mechanical properties of the cementitious material. The denser microstructure at 28 days compared to 3 days may be observed, which can be attributed to the ongoing hydration of cement phases combined with the pozzolanic reactions of silica fume and trass, which fills the pores with CSH. The hydration process is enhanced by the PC due to its porous structure, facilitating the storage and gradual release of water to support cement hydration over time. A higher amount of portlandite crystals is visible at 3 days of curing, owing to a rapid rate of hydration of alite and belite phases and a slower rate of pozzolanic reaction. Portlandite is observed at 28 days, which could be due to the gradual release of water from water-bearing pores in the PC, facilitating continuous hydration beyond the initial curing phase. The SEM images at 3 days indicate earlier CSH gel. At 28 days, as more CSH fills the capillary pores, the overall microstructure becomes denser and less porous. Between 3 days and 28 days, a decrease in the amount of ettringite crystals by 28 days, which was also observed in the XRD results. Ettringite crystals form early during cement hydration when the pH of the cement paste is higher due to the presence of portlandite. Over time, the silica fume and trass lime can consume portlandite to form secondary CSH, thus8781485 64Attorney Docket No.: UWYO / 0131PClowering pH of the matrix and destabilizing ettringite, which converts to monosulfate. The decreasing appearance of ettringite at 28 days, which may be due to the conversion to monosulfates, is supported by the reduction of sulfur content at 28 days through EDS analysis.

[0216] Figure 36 illustrates a graph of the TG-DT curves for PCA after 7 days and 28 days of curing. The dehydration kinetics of the PCA may be controlled by CSH, CH, and CaCOs. The total mass loss observed for the PCA was 22% at 7 days and 24% at 28 days. An increased loss of mass at 28 days may be due to the increased formation of hydration products and thermally liable phases, such as CSH, CH, and CaCOs. The difference in mass loss is minimal between 7 days and 28 days of curing, indicating a comparable degree of hydration at both ages. The UCS test indicates that the PCA gain their strength by 7 days (73%). Three derivative mass losses are observed at three different temperature ranges: 10°C-200°C, 400°C-600°C, 600°C-800°C. Moss loss in the range of 10°C-200°C may be attributed to the loss of capillary water and dehydration of CSH and ettringite, which is less prominent at 7 days compared to 28 days. The loss of capillary water and dehydration of CSH and ettringite indicated a more advanced stage of hydration at 28 days compared to 7 days, which may be facilitated by ongoing pozzolanic reaction contributed by silica fume and trass. The high water-holding capacity of the porous PCA significantly contributes to sustaining the hydration process by providing internal curing water over time, allowing for the formation of CSH products. The derivative mass loss at around 450°C is mainly due to the dehydroxylation of CH. Quick lime in TL facilitates the formation of CH throughout the hydration process and the formation of CSH through pozzolanic contribution of trass.

[0217] The consistent sharp peaks in derivative weight loss at both ages after 650°C are indicative of the decomposition of calcium carbonate. The presence of CaCOs in PCA is linked to the carbonation of portlandite as well as impurities present in PC ash. The presence of CaCOs at both ages suggests that the interconnected porous structure of PC may have facilitated the diffusion of CO2 to enhance carbonation. The incorporation of highly porous materials such as PC into cementitious matrices enhances CO2 diffusion, thus 8781485 65Attorney Docket No.: UWYO / 0131PCaccelerating carbonation reactions and promoting the formation of CaCOs. The interconnected pore structure of PC facilitates the ingress of CO2, which reacts with the calcium bearing phases such as portlandite, resulting in increased CaCOs precipitation within the matrix.

[0218] Figure 37 A illustrates a micrograph of an SEM image for the PCA mortar. Figure 37B illustrates a micrograph of an SEM image for the Lummis aggregate mortar. The interfacial transition zone (ITZ) around PCA is intact and devoid of any cracks. There is no evidence of cracks propagating into the cement paste either, suggesting the PCA is non-susceptible to ASR. Some cracks observed in the cement paste in PCA mortar samples can be attributed to the difference in thermal expansion between PCA and cement paste. In Lummis mortar, cracks inside the sand particles as well as the ITZ are observed. The cracks propagate radially into the cement paste, indicating the propagates of ASR reaction into the cement paste from the aggregates.

[0219] Figure 38 illustrates a graph of the expansion results for mortar bar samples immersed in NaOH solution for 28 days. The average expansion results of the three mortar bar samples for each aggregate type. Expansions of less than 0.10% at 14 days under NaOH immersion indicate innocuous behavior. Expansion of more than 0.2% is indicative of potentially deleterious expansion. Mortar bars with expansions between 0.10% and 0.20% have marginal behavior, including innocuous and deleterious aggregates. Mortar bars with PCA had the lowest average expansion among the mixes at 14 days, with an average expansion of 0.06%. The reactive Lummis aggregate mortar bars demonstrated the highest expansion at 14 days, with an average expansion of 0.26%, whereas mortar bars with Collins-pit aggregates recorded an average expansion of 0.07%. Granite and pea-gravel mortar bars recorded 0.14% and 0.09% average expansion, respectively, in the same period of time. At 28 days, the mortar bars of all four natural aggregates demonstrates more than 0.10% expansion, while the PCA had an expansion of less than 0.10%. The performance of PCA may be due to the high Ca / Si ratio, the relative lack of amorphous silica, and the formation of a dense microstructure that inhibits alkali ingress and silica dissolution-factors that collectively suppress ASR gel 8781485 66Attorney Docket No.: UWYO / 0131PCformation and expansion. The sudden swelling of PCA mortar bars, > 0.04% at 3 days, can be attributed to the expansion behavior of PCA due to the porous microstructure of PC and its ability to absorb water. PCA material increases in volume when soaked in water.

[0220] Figure 39 illustrates a graph of the of the relationship between expansion and UCS of mortars. Lummis sand, which has a comparable specific gravity to Collins pit, granite, and pea gravel, showed a compressive strength in a similar range of about 38 MPa to about 42 MPa while having the highest expansion (>0.20%). In contrast, PCA mortar cubes demonstrated lower compressive strength (about 37 MPa) but the lowest expansion (<0.08%), indicating that PCA offers improvement in ASR resistance with only a modest reduction in strength.

[0221] Figure 40A illustrates a micrograph of a SEM image of the PCA mortar. Figure 40B illustrates a graph of the EDS spectrum of the PCA mortar. Figure 40C illustrates a micrograph of the elemental mapping of carbon in the PCA mortar. Figure 40D illustrates a micrograph of the elemental mapping of sodium in the PCA mortar. Figure 40E illustrates a micrograph of the elemental mapping of aluminum in the PCA mortar. Figure 40F illustrates a micrograph of the elemental mapping of silicon in the PCA mortar. Figure 40G illustrates a micrograph of the elemental mapping of potassium in the PCA mortar. Figure 40H illustrates a micrograph of the elemental mapping of calcium in the PCA mortar. Figure 41A illustrates a micrograph of a SEM image of the Lummis mortar. Figure 41 B illustrates a graph of the EDS spectrum of the Lummis mortar. Figure 41 C illustrates a micrograph of the elemental mapping of carbon in the Lummis mortar. Figure 41 D illustrates a micrograph of the elemental mapping of sodium in the Lummis mortar. Figure 41 E illustrates a micrograph of the elemental mapping of aluminum in the Lummis mortar. Figure 41 F illustrates a micrograph of the elemental mapping of silicon in the Lummis mortar. Figure 41 G illustrates a micrograph of the elemental mapping of potassium in the Lummis mortar. Figure 41 H illustrates a micrograph of the elemental mapping of calcium in the Lummis mortar.8781485 67Attorney Docket No.: UWYO / 0131PC

[0222] Table 23 is a summary of the EDS mapping results for PCA and Lummis mortar samples. The PCA samples have a high average Ca / Si ratio of 4.78 compared to that of the Lummis aggregate (0.14), indicating minimal presence of reactive silica and CH in the pores of the PCA. The presence of reactive amorphous silica in aggregates, high alkali content in cement paste, and sufficient moisture enable the formation of ASR gel. ASR gels typically have Na / Si and K / Si ratios in the range of 0.1 -1.0 and 0.0-0.3, respectively, which align with the average ratios observed in the Lummis mortar. The ASR gels exhibit the highest swelling characteristics when the Ca / Si ratio is between 0.0 and 0.5. The Lummis mortar, with an average Ca / Si ratio of 0.14 indicate the high ASR susceptibility. The EDS mapping of PCA mortar indicates a high average Ca / Si ratio of 4.78, indicating the minimal presence of reactive silica in the PCA and paste. PCA, with Ca / Si of 4.78, may destabilize ASR gel formation when used in partial replacement reactive aggregates. The transformation of ASR gel into CSH products is possible at high Ca / Si ration. Similarly, the K / Si ratio of PCA (0.09) is lower than reactive Lummis aggregate (0.22), indicating the PCA has a suppressing effect on ASR gel swelling. The higher Na / K ratio in PCA may be due to the contamination of NaOH solution on the samples. In EDS mapping, scattered presence of calcium and oxygen is indicative of calcium-bearing phases such as portlandite, CaCOs, and calcium silicate hydrate within the pores of the PCA, indicating that CH is present in the pores of PCA and pozzolanic reactions are continuing after 28 days of curing.Table 23. Summary of EDS Mapping Results for PCA and Lummis Mortar Samples.Mortar Mix (Na + K) / Si Ca / Si Na / K K / Si Na / Si PCA 1.74 4.78 29.84 0.09 1.64 Lummis Aggregate 0.44 0.14 0.68 0.22 0.22

[0223] PCA demonstrated promising attributes in terms of density, ASR resistance, microstructural evolution, environmental sustainability, and internal curing potential compared to other conventional LWAs such as expanded clay, sintered fly ash, and expanded glass. The dry loose bulk density of PCA (8108781485 68Attorney Docket No.: UWYO / 0131PCkg / m3- 850 kg / m3) is within the limit specified by ASTM C330 for structural LWA and is comparable to that of pumice (480 kg / m3- 880 kg / m3), expanded slate (560 kg / m3- 860 kg / m3), and sintered fly ash (770 kg / m3- 960 kg / m3) aggregates. The water absorption capacity of PCA is less than that of expanded clay (32%-41 %) and comparable to sintered fly ash (24%-25%). Prewetting techniques may be utilized to achieve the saturated surface dry (SSD) condition can be used to improve workability. The SSD condition may improve slump, reduce autogenous shrinkage, and help optimize the microstructure of the concrete through internal curing. AMBT results showed that the 14-day expansion of 0.06% for PCA is lower than expanded glass (0.09%), expanded clay (0.10%), and perlite (0.13%), indicating its resistant behavior of ASR. Other LWAs, while displaying innocuous behavior in AMBT when paired with silica fume, may develop cracks internally owing to high amorphous silica content. PCA, however, demonstrated intact internal structure attributed to a high Ca / Si ratio with low amorphous silica, denser microstructure, and toughness. In terms of toughness and structural integrity, PCA demonstrated comparable LA Abrasion loss to LWAs like clay and shale (17%-30% loss) and better than natural aggregates like crushed marble (35%).

[0224] Coupled with the high compressive strength of PCA blocks that exceed 50 MPa, PCA demonstrates good mechanical resilience and strong potential for use in structural concrete. These properties are supported by the dense microstructure, as confirmed by SEM and XRD analyses, which indicate progressive formation of hydration products, including CSH, CH, and ettringite, contributing to enhanced matrix densification and long-term durability. PCA production does not require energy-intensive rotary kiln sintering at temperatures exceeding 1100 °C, like expanded clay or sintered fly ash. PCA is instead produced using cold-bonding processes at ambient conditions, eliminating the need for fossil-fuel firing and reducing energy consumption and associated CO2 emissions.Experiment 4:8781485 69Attorney Docket No.: UWYO / 0131PC

[0225] Table 24 is a summary of the mixing proportions for concrete prism test. A concrete prism test (CPT) was performed on concrete specimens. For CPT, concrete mixes with four different aggregate combinations were used: PC coarse and Collins sand (CC-CS), Granite coarse and Collins sand (GC-CS), Pea gravel and Lummis sand (PG-LS), and Pea gravel and PC fine (PG-CF). Sodium hydroxide (NaOH) solution was added as admixture during the concrete mixing as required to bring the total alkali content of cement to 1.25% by mass. The amount of NaOH to be added to concrete mixes were calculated as 3.42 kg / m3The equivalent alkali content of the cement was found to be 0.63% according to ball mill test report provided by the manufacturer.Table 24. Summary of Mixing Proportions for Concrete Prism TestSN Mix ID Ingredients (kg / m3)Cementitious Coarse Fine w / c NaOH Materials Aggregate Aggregate1 GC-CS 420 1189 642 0.43 3.42 2 CC-CS 420 714 642 0.45 3.42 3 PG-LS 420 1175 652 0.43 3.42 4 PG-CF 420 1175 416 0.43 3.42

[0226] Figure 42 illustrates a graph of the average expansion results of the concrete prism specimens. CPT was conducted in accordance with ASTM C1293 to evaluate the long-term alkali-silica reactivity (ASR) for four different concrete specimens. To evaluate the reactivity of a coarse aggregate, a nonreactive fine aggregate is used and vice versa. A nonreactive coarse / fine aggregate is defined as an aggregate that develops an expansion in the AMBT of less than 0.10 % at 14 days. The expansion limit for ASTM C 1293 is 0.04 percent (at one year for aggregates, two years for preventive measures). According to Canadian standards (CSA), the reactivity of an aggregate is classified based on expansion at one year, with expansions between 0.04% and 0.12% considered moderately reactive, and expansions greater than 0.12 % are considered highly reactive. Concrete samples using pea gravel and Lummis sand (PG-LS) exhibited the highest expansion of 0.27% among all 8781485 70Attorney Docket No.: UWYO / 0131PCmixes, showing highly reactive behavior. Concrete samples using Granite coarse-Collins sand (GC-CS) and pea gravel-Char fine (PG-CF) combinations showed moderately reactive behavior with expansions of 0.070% and 0.049%, respectively.

[0227] The moderately reactive behavior of granite aggregates exceeded the expansion limit in short term AMBT test. The expansive nature in the PC-CF specimen is likely due to the expansive behavior of pea gravel, which was very close to the limit in short term mortar bar test. PC coarse and Collins sand combination (CC-CS) showed the non-reactive nature with the lowest expansion of 0.035%. This matches the AMBT test results where both aggregates showed innocuous behavior with expansion of 0.06% and 0.07% respectively. The exudation of ASR gel and efflorescence of sodium carbonate is observable in PG-LS specimens followed by GC-CS. For PG-LS specimens, ASR gel exudations and longitudinal and transverse cracking induced from ASR are visible. Specimens with either coarse or fine PCA (CC-CS and PC-CF) showed minimal or no signs of gel exudations or surface cracking.EMBODIMENTS LISTING

[0228] The present disclosure provides, among other things, the following embodiments, each of which can be considered as optionally including any alternate embodiment.

[0229] Clause 1. A composition, comprising:pyrolysis char (PC);cementitious material;superplasticizer;water;silica fume; andone or more additives.

[0230] Clause 2. The composition of clause 1, comprising:about 25% to about 35% PC;8781485 71Attorney Docket No.: UWYO / 0131PCabout 50% to about 60% cementitious material;about 5% to about 10% additives;about 2.5% to about 7.5% silica fume; andabout 0.5% to about 2.5% superplasticizer.

[0231] Clause 3. The composition of clause 1, wherein the additives comprise trass, trass lime, alkaline activators, fly ash, air entraining (AE) agents, algae, or graphene oxide (GO).

[0232] Clause 4. The composition of clause 1, wherein the superplasticizer comprises polycarboxylic ether polymer (such as BASF Melflux), a polycarboxylate ether, a sulfonated naphthalene formaldehyde, a sulfonated melamine formaldehyde, a lignosulfate, or an acrylic polymer.

[0233] Clause 5. The composition of clause 1, wherein the silica fume comprises an amorphous micronized grey silicon dioxide pozzolan, a densified SF, or an undensified SF.

[0234] Clause 6. The composition of clause 1, wherein the silica fume comprises BASF Melflux 2651 F.

[0235] Clause 7. The composition of clause 5, wherein the densified SF comprises Trinic R-E-D 105WS, Trinic R-E-D 106 pm, Trinic Pozz Plus, Trinic Z3-95, or DMI NanoPozz 100-D.

[0236] Clause 8. The composition of clause 5, wherein the undensified SF comprises Riteks microfume 106 pm.

[0237] Clause 9. The composition of clause 1, wherein the composition has an expansion of less than 0.1% at 14 days under NaOH immersion.

[0238] Clause 10. The composition of clause 1, wherein the composition has a water absorption of about 20% to about 30%.

[0239] Clause 11. The composition of clause 1, wherein the composition has a water absorption of about 20% to about 30% in 24 hours.8781485 72Attorney Docket No.: UWYO / 0131PC

[0240] Clause 12. The composition of clause 1, wherein the composition has a specific gravity value of PCA is about 1.3 to about 1.4.

[0241] Clause 13. The composition of clause 1, wherein the composition has a percentage of friable particles for coarse PCA is less than about 0.5%.

[0242] Clause 14. The composition of clause 1, wherein the PC is derived from coal materials.

[0243] Clause 15. The composition of clause 14, wherein the coal materials are sub-bituminous coal.

[0244] Clause 16. The composition of clause 15, wherein the sub-bituminous coal is produced from the Powder River Basin (PRB) coal.

[0245] Clause 17. The composition of clause 1, wherein the PC is chemically processed from the PRB coal.

[0246] Clause 18. The composition of clause 1, wherein The PC is formed by pyrolyzing the coal material in a furnace up to a temperature of about 850°C.

[0247] Clause 19. The composition of clause 1, wherein the cementitious material comprises ordinary Portland Cement (Type I, Type II, Type III, Type IV, Type V), slag cement, slag-modified Portland cement, expansive cement, white cement, water-repellant cement, masonry cement Type N or Type S, cement line, Type S, Mortar cement, oil well cement, plastic cement, rapid setting cement, Portland blast-furnace slag cement, Portlandpozzolans cement, and pozzolans-modified Portland cement, ground granulated blast furnace slag (GGBFS), fly ash (e.g., Class C fly ash), ground limestone, and combinations thereof.

[0248] Clause 20. The composition of clause 1, wherein the specific gravity of the cementitious material is about 3.15.

[0249] Clause 21. A method of forming a composition, comprising: 8781485 73Attorney Docket No.: UWYO / 0131PCmixing a superplasticizer with water to form a wet mixture;mixing additives, silica fume, and PC to form a dry mixture;mixing the wet mixture and the dry mixture to form a pyrolysis char (PC) mixture;curing the PC mixture to form a PC block (PCB); andcrushing the PCB to form a PC aggregate (PCA).

[0250] Clause 22. The method of clause 21, further comprising pouring the PC mixture into a mold.

[0251] Clause 23. The method of clause 22, wherein pouring the PC mixture into the mold further comprises compressing the PC mixture into the mold using a hydraulic press at about 10 tons to about 15 tons.

[0252] Clause 24. The method of clause 21, further comprising sealing the PC mixture to retain moisture for about 20 hours to about 28 hours.

[0253] Clause 25. The method of clause 21, wherein curing the PC mixture to form a PCB comprises curing the PC mixture in a wet room at a humidity of about 90% and about 95% for about 24 days to about 32 days.

[0254] Clause 26. The method of clause 21, further comprising sieving the PCA to determine a particle size distribution.

[0255] Clause 27. The method of clause 26, wherein sieving the PCA to determine the particle size distribution comprises:classifying PCA retained by a No. 4 sieve as coarse PCA; and classifying PCA passing through the No. 4 sieve as fine PCA.

[0256] Clause 28. The method of clause 21, wherein mixing the superplasticizer with water to form a wet mixture comprises mixing the superplasticizer and the water for about 90 second to about 150 seconds.

[0257] Clause 29. The method of clause 21, wherein mixing the additives, PC, and silica fume to form a dry mixture comprises mixing the additives, PC, and silica fume for about 150 seconds to about 210 seconds.8781485 74Attorney Docket No.: UWYO / 0131PC

[0258] Clause 30. The method of clause 21, wherein mixing the wet mixture and the dry mixture to form a PCA mixture comprises mixing the wet mixture and dry mixture for about 150 seconds to about 210 seconds.

[0259] Clause 31. A method of forming a concrete, comprising:mixing an air entraining agent, a water reducer, and water to form a solution;mixing a fine pyrolysis char aggregate (PCA), a course PCA, a cementitious material, water, and the solution to form a PCA concrete, wherein the fine PCA and the coarse PCA comprise:about 25% to about 35% PC;about 50% to about 60% cementitious material;about 5% to about 10% additives;about 2.5% to about 7.5% silica fume; andabout 0.5% to about 2.5% superplasticizer; andcuring the PCA concrete to form a PCA concrete specimen.

[0260] Clause 32. The method of clause 31, further comprising pouring the PCA concrete into a mold.

[0261] Clause 33. The method of clause 32, wherein the pouring of the PCA concrete into a mold further comprises:pouring a first layer the PCA concrete into the mold;tamping the PCA concrete into the mold using a tamping rod; tapping the outside of the mold with a mallet; andpouring a second layer of the PCA concrete into the mold.

[0262] Clause 34. The method of clause 31, wherein curing the PCA concrete to form a PCA concrete specimen comprises:covering the PCA concrete with a waterproof plastic;curing the PCA concrete for about 20 hours to about 28 hours; and transferring the PCA concrete to a wet room for continuous curing.8781485 75Attorney Docket No.: UWYO / 0131PC

[0263] Clause 35. The method of clause 31, wherein mixing a fine pyrolysis char aggregate (PCA), a course PCA, a cementitious material, water, and the solution to form a PCA concrete further comprises mixing the PCA concrete in a mixer for about 1 minute to about 5 minutes.

[0264] Clause 36. The method of clause 31, wherein the PCA concrete specimen has an unconfined compressive strength of about 25 MPa to about 45 MPa.

[0265] Clause 37. The method of clause 31, wherein the PCA concrete specimen has a flexural strength of about 3 MPa to about 5 MPa.

[0266] Clause 38. The method of clause 31, wherein the PCA concrete specimen has a tensile strength of about 2 MPa to about 4 MPa.

[0267] Clause 39. The method of clause 31, wherein the PCA concrete specimen has a bulk density of about 1500 kg / m3to about 2500 kg / m3

[0268] Clause 40. The method of clause 31, wherein the PCA concrete specimen has a modulus of elasticity of about 10 GPa to about 40 GPa.

[0269] As is apparent from the foregoing general description and the specific aspects, while forms of the aspects have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including.” Likewise whenever a composition, process operation, process operations, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “Is” preceding the recitation of the composition, process operation, process operations, element, or elements and vice versa, such as the terms “comprising,” “consisting essentially of,” “consisting of” also include the product of the combinations of elements listed after the term.8781485 76Attorney Docket No.: UWYO / 0131PC

[0270] For purposes of this present disclosure, and unless otherwise specified, all numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and consider experimental error and variations that would be expected by a person having ordinary skill in the art. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. For example, the recitation of the numerical range 1 to 5 includes the subranges 1 to 4, 1.5 to 4.5, 1 to 2, among other subranges. As another example, the recitation of the numerical ranges 1 to 5, such as 2 to 4, includes the subranges 1 to 4 and 2 to 5, among other subranges. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. For example, the recitation of the numerical range 1 to 5 includes the numbers 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, among other numbers. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0271] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.8781485 77

Claims

Attorney Docket No.: UWYO / 0131PCWhat is claimed is:

1. A composition, comprising:pyrolysis char (PC);cementitious material;superplasticizer;water;silica fume; andone or more additives.

2. The composition of claim 1, comprising:about 25% to about 35% PC;about 50% to about 60% cementitious material;about 5% to about 10% additive;about 2.5% to about 7.5% silica fume; andabout 0.5% to about 2.5% superplasticizer.

3. The composition of claim 1, wherein the additive comprises trass, trass lime, alkaline activators, fly ash, an air entraining (AE) agent, algae, or graphene oxide (GO).

4. The composition of claim 1, wherein the superplasticizer comprises polycarboxylic ether polymer (such as BASF Melflux), a polycarboxylate ether, a sulfonated naphthalene formaldehyde, a sulfonated melamine formaldehyde, a lignosulfate, or an acrylic polymer.

5. The composition of claim 1, wherein the silica fume comprises an amorphous micronized grey silicon dioxide pozzolan, a densified SF, or an undensified SF.

6. A method of forming a composition, comprising:mixing a superplasticizer with water to form a wet mixture;mixing one or more additives, silica fume, and PC to form a dry mixture; 8781485 78Attorney Docket No.: UWYO / 0131PCmixing the wet mixture and the dry mixture to form a pyrolysis char (PC) mixture;curing the PC mixture to form a PC block (PCB); andcrushing the PCB to form a PC aggregate (PCA).

7. The method of claim 6, further comprising:pouring the PC mixture into a mold.

8. The method of claim 7, wherein pouring the PC mixture into the mold further comprises compressing the PC mixture into the mold using a hydraulic press at about 10 tons to about 15 tons.

9. The method of claim 6, further comprising:sealing the PC mixture to retain moisture for about 20 hours to about 28 hours.

10. The method of claim 6, wherein curing the PC mixture to form a PCB comprises curing the PC mixture in a wet room at a humidity of about 90% and about 95% for about 24 days to about 32 days.

11. A method of forming a concrete, comprising:mixing an air entraining agent, a water reducer, and water to form a solution;mixing a fine pyrolysis char aggregate (PCA), a course PCA, a cementitious material, water, and the solution to form a PCA concrete, wherein the fine PCA and the coarse PCA comprise:about 25% to about 35% PC;about 50% to about 60% cementitious material;about 5% to about 10% additive;about 2.5% to about 7.5% silica fume; andabout 0.5% to about 2.5% superplasticizer; andcuring the PCA concrete.8781485 79Attorney Docket No.: UWYO / 0131PC12. The method of claim 11, further comprising pouring the PCA concrete into a mold.

13. The method of claim 12, wherein the pouring of the PCA concrete into a mold further comprises:pouring a first layer the PCA concrete into the mold;tamping the PCA concrete into the mold using a tamping rod; tapping the outside of the mold with a mallet; andpouring a second layer of the PCA concrete into the mold.

14. The method of claim 11, wherein curing the PCA concrete to form a PCA concrete specimen comprises:covering the PCA concrete with a waterproof plastic;curing the PCA concrete for about 20 hours to about 28 hours; and transferring the PCA concrete to a wet room for continuous curing.

15. The method of claim 11, wherein mixing a fine pyrolysis char aggregate (PCA), a course PCA, a cementitious material, water, and the solution to form a PCA concrete further comprises mixing the PCA concrete in a mixer for about 1 minute to about 5 minutes.8781485 80

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