Composition and method for concrete repair

Abstract

Compositions and methods are disclosed including a composition for concrete repair. A composition can include a carrier, one or more encapsulants, one or more biomineralizing agents encapsulated within the encapsulants, and one or more additives within the carrier. A method can include providing a composition and applying the composition to concrete.

Description

TITLE: COMPOSITION AND METHOD FOR CONCRETE REPAIRINVENTORS: CAITLIN ADAMS, MOHAMMAD IRFAN IQBAL, GEETIKAMISHRA, CANSU ACARTURK, HYUN-WOO JOO, AMIR YAGHOOB FARNAM, WILFRED VENCIL SRUBAR III, PARSA NAMAKIARAGHI, IRENE VERDU, MIJA HUBLER, CHRISTOPHER SALES, SOBIA ANJUMSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] This invention was made with government support under grant number D23AC00043, awarded by DOD / DARPA. The government has certain rights in the invention.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Number 63 / 768,841, entitled “METHOD AND COMPOSITION FOR REPAIR AND PROLONGED FUNCTION OF CONCRETE UTILIZING BIOLOGICAL APPLICATION,’’ and filed March 7, 2025, and to U.S. Provisional Application Number 63 / 656.152, entitled “DEVELOPMENT OF ADVANCED VASCULAR DELIVERY TECHNIQUES TO TRANSPORT BIOFUNCTIONAL AGENTS IN CRACKED CONCRETE FOR SELF-HEALING APPLICATIONS,’’ and filed June 5, 2024, the disclosures of which are herein incorporated by this reference in their entirety.TECHNICAL FIELD

[0003] This disclosure generally relates to concrete, pavement, and other reinforced structures. More particularly, examples of the disclosure relate to compositions and methods for repair of concrete.BACKGROUND

[0004] Structural concrete, pavements, and other reinforced structures crack and degrade over time. Current repair technologies generally include consistent maintenance, as repair material may be applied to fill or fix a crack a single time and then be reapplied as the concrete continues to crack and degrade. Alternatively, current biomineralization repair technologies often require additives be included in a fresh concrete composition at the time offormation, i.e., before the concrete has set. Biomineralization has been shown to seal fractures effectively, but prolonged self-repair has not been achieved due to challenges with optimizing the microbial activity in high-pH concrete environments, bacterial desiccation over time, and a lack of nutrients after an initial grow th period.

[0005] Therefore, in view of the above, there is generally a desire for compositions and methods that provide repeated repair to existing concrete. Furthermore, there is a general desire for sustainable and relatively low cost methods and compositions for such applications.

[0006] Any discussion, including discussion of problems and solutions, set forth in this section, has been included in this disclosure solely for the purpose of providing a context for the present disclosure, and should not be taken as an admission that any or all of the discussion was known at the time the invention was made or otherwise constitutes prior art.SUMMARY

[0007] This summary' may introduce a selection of concepts in a simplified form, which may be described in further detail below. This summary is not intended to necessarily identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] Various embodiments of the present disclosure relate to concrete repair compositions and methods. Exemplary compositions can repair damaged concrete by a biological treatment which may be capable of restoring strength to the concrete. The concrete may be restored up to the strength of the original concrete sample. In accordance with examples of the disclosure, a portion of the composition may remain dormant in the concrete after an initial repair and may repair future damage.

[0009] The composition may include one or more biomineralization agents and one or more encapsulants, configured to encapsulate the one or more biomineralization agents and provide prolonged repair. The biomineralization agent(s) may include bacteria, nutrients, and / or the like along or with additives. The encapsulants may release encapsulated biomineralization agents by pressure or by moisture or the like. The composition may include flax and / or basalt fibers, which may serve to reinforce the concrete. The compositions and / or methods may be environmentally sustainable, have an overall low cost, and employ relatively low' or little maintenance.

[0010] Exemplary embodiments of the disclosure relate to compositions for concrete repair. Exemplary compositions include a carrier, one or more encapsulants, one or more biomineralizing agents, and one or more additives. In accordance with examples of thedisclosure, the one or more biomineralizing agents can be encapsulated within the one or more encapsulants. The one or more additives can be within the carrier. The carrier can include one or more of a polymer or a hydrogel. The hydrogel can include one or more of agar, sodium alginate, or a gelatin. The one or more biomineralizing agents can include, for example, bacteria and / or enzymes. The bacteria can include, for example, one or more of ureolytic and non-ureolytic bacteria. By w ay of particular example, the bacteria can include one or more of Sporosarcina pasteurii. Lysinibacillus sphaericus. or Komagataeibacter xylinus. The enzymes can include, for example, urease or the like. The one or more encapsulants can include, for example, one or more of Lysinibacillus sphaericus, sodium alginate, calcium acetate, or nutrient media. The one or more encapsulants can comprise one or more of spray dried encapsulants, emulsion encapsulants, or inverse suspension encapsulants. The one or more additives can include fibers or grains. The fibers can include at least one of flax fibers or basalt fibers.

[0011] In accordance with various embodiments of the disclosure, a composition for concrete repair can include a gel and a biomineralizing agent. The gel can be or include bacterial nanocellulose.

[0012] Additional embodiments of the disclosure relate to a method of repairing concrete. The method can include providing a composition as described herein and applying the composition to concrete. In accordance with examples of the disclosure, applying the composition may include injecting the composition into the concrete, providing a viscous paste within a defect of the concrete, spraying the composition onto the concrete, or laying a film including the composition on the concrete. Applying the composition may include forming a channel within the concrete and injecting the composition into the channel. In accordance with particular examples, the composition includes a carrier that includes sodium alginate, and biomineralizing agents, which include Lysinibacillus sphaericus. The method can include wetting the concrete before applying the composition.

[0013] In accordance with further embodiments of the disclosure, a method for repairing concrete can include forming a bacterial nanocellulose pellicle and applying the bacterial nanocellulose pellicle to concrete. The bacterial nanocellulose pellicle can include one or more biomineralizing agents.

[0014] For the purpose of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure may have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment. Thus, for example, one mayrecognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0015] These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To facilitate further description of the embodiments, the following drawings are provided in which:

[0017] FIG. 1 illustrates an exemplary method for concrete repair, according to an embodiment;

[0018] FIG. 2 illustrates an exemplary method for concrete repair, according to an embodiment;

[0019] FIG. 3 illustrates an exemplary method for concrete repair, according to an embodiment;

[0020] FIG. 4 illustrates an exemplary microbial induced calcium carbonate production pathway, according to an embodiment;

[0021] FIG. 5 illustrates an exemplary bacterial growth curve, according to an embodiment;

[0022] FIG. 6 illustrates exemplary’ growth curves for L. sphaericus inoculated in various culture media, according to exemplary’ embodiments;

[0023] FIG. 7 illustrates exemplary’ ureolysis reaction curves according to various initial urea concentrations, according to an embodiment;

[0024] FIG. 8 illustrates the relationship between electrical conductivity and the hydrolyzed urea concentration;

[0025] FIG. 9 illustrates the hydrolyzed urea concentrations of the curves of FIG. 7, according to an embodiment;

[0026] FIG. 10 illustrates initial ureolysis rates for various initial urea concentrations, according to an embodiment;

[0027] FIG. 11 illustrates the initial urea hydrolysis rate versus the initial urea concentration, according to an embodiment;

[0028] FIG. 12 illustrates exemplary microbial induced calcium carbonate production (MICCP) reactions and resultant biomass, according to an embodiment;

[0029] FIG. 13 illustrates exemplary obtained biomass versus time curves, where reactions in a stationary phase are illustrated in a rectangle, according to an embodiment;

[0030] FIG. 14 illustrates exemplary’ concentration curves for urea, CO?2'. Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP in a urea-limited environment, according to an embodiment;

[0031] FIG. 15 illustrates exemplary concentration curves in a solution for carbonic acid, bicarbonate, and carbonate ions versus the pH of the solution, according to an embodiment;

[0032] FIG. 16 illustrates an exemplary pH curve for a solution during ammonia ionization, according to an embodiment;

[0033] FIG. 17 illustrates exemplary' concentration curv es for urea, CO?2'. Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP in a biomineralizing agentlimited environment, according to an embodiment;

[0034] FIG. 18 illustrates an exemplary embodiment of a self-healing concrete comprising one or more vascular channels, according to an embodiment;

[0035] FIG. 19 illustrates exemplary' concentration curv es for urea, CO?2'. Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP at a specific location, according to an embodiment;

[0036] FIG. 20A illustrates exemplary’ concentrations of biomineralizing agents versus distance after varying amounts of time, according to an embodiment;

[0037] FIG. 20B illustrates exemplary’ concentrations of urea versus distance after varying amounts of time, according to an embodiment;

[0038] FIG. 20C illustrates exemplary concentrations of NH3 versus distance after varying amounts of time, according to an embodiment;

[0039] FIG. 20D illustrates exemplary concentrations of CO?2' versus distance after varying amounts of time, according to an embodiment;

[0040] FIG. 20E illustrates exemplary concentrations of Ca2+versus distance after varying amounts of time, according to an embodiment;

[0041] FIG. 20F illustrates exemplary concentrations of calcium carbonate versus distance after varying amounts of time, according to an embodiment;

[0042] FIG. 21 illustrates treated and control damaged concrete samples, according to various embodiments;

[0043] FIG. 22 illustrates an exemplary schematic diagram of the mechanism for describing pH effects on enzymatic urea hydrolysis, according to an embodiment;

[0044] FIG. 23 A illustrates biomineralizing agent concentration curves for varying y values, according to an embodiment;

[0045] FIG. 23B illustrates biomineralizing agent concentration curves for varying a values, according to an embodiment;

[0046] FIG. 23C illustrates biomineralizing agent concentration curves for varying rmvalues, according to an embodiment;

[0047] FIG. 24 illustrates an exemplary equivalent material representation of a damaged concrete material after MICCP healing, according to an embodiment;

[0048] FIG. 25 illustrates an exemplary7schematic diagram for self-repair in concrete structures by vascularization, according to an embodiment;

[0049] FIG. 26 illustrates an exemplar}7process for self-repair of concrete by vascularization, according to an embodiment;

[0050] FIG. 27 illustrates exemplary distributions of a carrier in damaged concrete and having a channel formed therein, according to an embodiment;

[0051] FIG. 28 illustrates an exemplary concrete sample having a crack and a channel formed therein, according to an embodiment;

[0052] FIG. 29 illustrates an exemplary microscopic view of a carrier containing one or more biomineralizing agents applied to a concrete sample having a crack and a channel formed therein, according to an embodiment;

[0053] FIG. 30A illustrates an exemplar}7thermogravimetric analysis of a reference concrete, according to an embodiment;

[0054] FIG. 30B illustrates an exemplary thermogravimetric analysis of a concrete subjected to MICCP. according to an embodiment;

[0055] FIG. 31A illustrates an exemplary thermogravimetric analysis of concrete samples providing an amount of biological calcium carbonate collected per mg of dried powder for varying time periods after MICCP, according to an embodiment;

[0056] FIG. 3 IB illustrates an exemplary thermogravimetric analysis of concrete samples providing a mass of biological calcium carbonate collected for varying time periods after MICCP, according to an embodiment;

[0057] FIG. 32A illustrates several exemplary x-ray diffraction analyses of concrete for varying time periods, according to an embodiment;

[0058] FIG. 32B illustrates several exemplary x-ray diffraction analyses of concrete for varying time periods of MICCP, according to an embodiment;

[0059] FIG. 33A illustrates an exemplary7concrete sample having bacterial nanocellulose applied to a crack, according to an embodiment;

[0060] FIG. 33B illustrates the exemplary embodiment of FIG. 33A after a period of time, according to an embodiment;

[0061] FIG. 34A illustrates an exemplary damaged concrete sample treated with an in- situ formed composition including bacterial nanocellulose and additives, according to an embodiment;

[0062] FIG. 34B illustrates an exemplary damaged concrete sample treated with an in- situ formed composition including bacterial nanocellulose, additives, and enzymes, according to an embodiment.

[0063] It will be appreciated that elements in the figures are illustrated for simplicity7and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure.DETAILED DESCRIPTION

[0064] Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the disclosure extends beyond the specifically disclosed embodiments and / or uses of the disclosure and obvious modifications and equivalents thereof.Thus, it is intended that the scope of the disclosure should not be limited by the particular embodiments described herein.

[0065] Unless noted otherwise, illustrations presented herein are not necessarily meant to be actual views of any particular material, composition, structure, or method, but are merely representations that are used to describe embodiments of the disclosure.

[0066] Disclosed herein are compositions and methods for concrete repair. A composition for concrete repair may include a carrier, one or more encapsulants, one or more biomineralizing agents encapsulated within the one or more encapsulants, and one or more additives within the carrier. When applied to damaged concrete, the composition may fill defects and / or cracks in the concrete, may provide immediate strength to the concrete, and / or may continue to remain in the concrete for a prolonged period of time and provide further repair and strength upon an occurrence of future damage. Exemplary compositions disclosed herein may restore the concrete up to the original strength of the concrete. Exemplary' compositions and methods disclosed herein can provide repeated repair and prolonged healing to damaged concrete after a single application. Exemplary compositions and / or methods may be environmentally sustainable, have an overall low- cost, and / or employ minimal maintenance. Further, the composition may remain dormant in the concrete after an initial application and / or repair and may repair future damage. For example, a composition may be applied to damaged concrete to repair the damage. The concrete may later suffer further damage, and the composition originally applied may repair the further damage.

[0067] The carrier may comprise any suitable earner for delivering the composition to damaged concrete. For example, the carrier may include one or more of a polymer or a hydrogel. Exemplary embodiments of the carrier can include one or more of poly glutamic acid (PGA), bacterial cellulose, bacterial nanocellulose, sodium alginate, a gelatin, and / or agar. In various embodiments, PGA may be generated by bacillus hcheniformis, bacillus subtilis. or by any other suitable source for generation of PGA. An amount of the carrier in the composition can be from about 1% w / v to about 10% w / v of the composition%, from about 2% w / v to about 9% w / v, or from about 3% w / v to about 7% w / v. An amount of the carrier in the composition can be from about 1% w / w to about 10% w / w, from about 2% w / w to about 9% w / w, or from about 3% w / w to about 7% w / w. The carrier may be selected such that it allows the composition to disperse within the concrete and / or to remain in the concrete for prolonged periods of time, for example 7 days, 14 days, 28 days, 3 months, 6 months, 1 year, or longer.

[0068] The encapsulants may comprise one or more of spray dried encapsulants, emulsion encapsulants, and / or inverse suspension encapsulants. Any suitable encapsulant material and / or method for encapsulating the one or more biomineralizing agents may be used. In various embodiments, nutrients and / or additives may be encapsulated within the encapsulants. The encapsulants may be included within the composition and / or within the carrier. The encapsulants may be configured to provide prolonged repair. For example, the encapsulants may be released by pressure, by moisture, or by any other suitable mechanism. In this manner, the one or more biomineralizing agents and optionally nutrients and / or additives may be released into the concrete over a prolonged period of time or may be released into the concrete by an instance of damage, such as a crack in the concrete. For example, a crack in the concrete may expose one or more encapsulants to moisture, which may release the encapsulant and allow the one or more biomineralizing agents to be released into the crack. Encapsulation of biomineralizing agents and optionally nutrients, additives, and / or enzymes may mitigate desiccation and may provide sites for biomineralizing agent growth following periods of dormancy and / or low activity’. In an exemplary’ embodiment, the one or more encapsulants can contain one or more of Lysinibacillus sphaericus, sodium alginate, calcium acetate, or nutrient media. An amount of the encapsulants in the composition can be between about 1 wt% to about 10 wt%, between about 2 wt% and about 9 wt%, between about 2 wt% and about 5 wt%, between about 1 wt% and about 3 wt%, or be about 2 wt%.

[0069] The one or more biomineralizing agents can include bacteria and / or enzy mes. The bacteria can include any bacteria capable of inducing microbially induced calcium carbonate production (MICCP). For example, the bacteria may include one or more of ureolytic and non-ureolytic bacteria. For example, the bacteria may include one or more of Sporosarcina pasteurii, such as for example S. pasteurii ATCC 11859, Lysinibacillus sphaericus, such as for example L. sphaericus LMG 22257 and / or L. sphaericus ATCC 13805, Komagataeibacter xylinus, P. megaterium ATCC 14581, B. subtilis ATCC 11774. B. subtilis ATCC 6051. D. radiodurans MTCC 4465, B. miscanthi AK13, or H. halodenitrificans DSM 735. The enzymes may be capable of enzyme induced calcium carbonate precipitation (EICP). In various embodiments, the enzy mes may catalyze the MICCP. For example, the enzy mes can include urease. Urease may increase a rate of urea hydrolysis (ureolysis), which may increase a rate of MICCP. Further, ureolysis may increase the pH of the environment, which may increase the favorability' of calcium carbonate precipitation in the environment. In an exemplary embodiment, urea and water may be catalyzed by urease into carbamic acid and ammonia. Thecarbamic acid may react with water to form ammonia and carbonic acid. The ammonia may dissociate into ammonium and hydroxide, which may increase the pH of the environment. The carbonic acid may dissociate into bicarbonate and hydrogen. The bicarbonate may dissociate into carbonate ions and hydrogen. The carbonate ions may react with calcium ions to form calcium carbonate. Calcium ions may be provided to the concrete, for example within the carrier and / or as an additive, or may be present within the concrete, for example in the form of calcium hydroxide which may dissociate into calcium ions and hydroxide. Prolonged repair of concrete may be supported in aerobic regions of concrete defects primarily by microbially produced mineral production, and prolonged repair of concrete may be supported in anaerobic regions of concrete defects by enzy matic processes. An initial amount of the one or more biomineralizing agents in the composition can be up to 0.5 wt% or up to 1 wt%, or may be any suitable initial amount. The amount of the one or more biomineralizing agents may increase over time as the one or more biomineralizing agents grow and / or multiply.

[0070] The one or more additives can include, for example, fibers or grains. The fibers may be any suitable fibers for supporting the composition within the concrete and / or prolonging repair. The fibers may reinforce the concrete and / or provide strength to the concrete upon repair. The fibers may include, for example, flax fibers, basalt fibers, and / or plant-based fibers such as plant-based wastes. The grains may be, for example, glass beads. The grains may be acid-washed glass beads. A particle size of the grains may be about 1mm or smaller, 106pm or smaller, about 100pm or smaller, about 90pm or smaller, between about 90pm and about 106pm, between about 30pm and about 90pm, between about 20pm and about 30pm, between about 10pm and about 30pm, between about 1pm and about 30pm, or less than about 30pm. An amount of the one or more additives in the composition can be between about 5% w / w to about 97.5% w / w, between about 10% w / w and about 80% w / w or between about 15% w / w and about 85% w / w.

[0071] With reference to FIG. 1, an exemplary method 100 for concrete repair is illustrated. The method 100 may include providing a composition 110 and applying the composition to the concrete 120. The composition may be any of the compositions described herein. With reference to FIG. 2, an exemplary7method 100 for concrete repair is further illustrated. The step of applying the composition 120 may include one or more of injecting the composition into the concrete and / or a defect 221. providing a viscous paste within a defect of the concrete 222, spraying the composition onto and / or into the concrete and / or defect 223, laying a film comprising any of the compositions described herein onto the concrete 224, and / orforming a channel within the concrete 225 and injecting any of the compositions described herein into the channel 226. Any suitable method of applying any of the compositions described herein to the concrete may be used. In various embodiments, the viscous paste may comprise the composition. In various embodiments, the film may comprise bacterial cellulose and / or bacterial nanocellulose. In various embodiments, the carrier may comprise sodium alginate and / or the one or more biomineralizing agents may comprise Lysinibacillus sphaericus. The method 100 may further include wetting the concrete 227 prior to applying the composition to the concrete 120. The wetting the concrete 227 may be, for example, by water.

[0072] With reference to FIG. 3, an exemplary method 300 for concrete repair is illustrated. The method 300 may include forming a bacterial nanocellulose pellicle 310 and applying the bacterial nanocellulose pellicle to the concrete 320. The bacterial nanocellulose pellicle may include one or more biomineralizing agents, such as exemplary biomineralizing agents described herein. The bacterial nanocellulose pellicle may include one or more additives and / or nutrients as described herein. In an exemplary embodiment, the nutrients may include glucose and / or minerals for supporting the one or more biomineralizing agents. The bacterial nanocellulose pellicle may comprise enzymes, such as those described herein. In an exemplary embodiment, the bacterial nanocellulose pellicle may be formed by using a bacteria and a medium. The bacteria may be, for example, Komagataeibacter xylinus ATCC 53524. The medium may be, for example, ATCC medium 1717. The medium may be adjusted to a pH value of between about 4.3 and about 4.4, which may promote bacterial nanocellulose production and may maintain bacterial viability. The K. xylinus may be inoculated into the medium. For example, the K. xylinus may be inoculated into the medium in a vent-capped culture bottle at a 1 :20 v / v ratio and may be cultivated in an incubator at 30 °C. The bacterial nanocellulose may be collected from the surface of the medium after a period of time, for example, after 3 days. The applying the bacterial nanocellulose pellicle to the concrete 320 may be by any suitable method, for example, by laying the pellicle on the concrete and / or within a defect of the concrete.

[0073] With reference to FIG. 4, an exemplary microbial induced calcium carbonate production pathway is illustrated. As discussed above, urea and water may be catalyzed by urease into carbamic acid and ammonia. The carbamic acid may react with water to form ammonia and carbonic acid. The ammonia may dissociate into ammonium and hydroxide, which may increase the pH of the environment. The carbonic acid may dissociate into bicarbonate and hydrogen. The bicarbonate may dissociate into carbonate ions and hydrogen.The carbonate ions may react with calcium ions to form calcium carbonate. Calcium ions may be attracted to and / or attach to the bacterial cell, for example due to a negative charge of the cell. In this manner, the cell may act as a nucleation site for calcium carbonate. The calcium carbonate may then attach to a defect and / or crack surface and fill a defect and / or crack within the concrete. In various embodiments, MICCP may result in aragonite, vaterite, and / or calcite polymorphs of calcium carbonate.

[0074] With reference to FIG. 5, an exemplary bacterial growth curve is illustrated. Initially, the bacteria may be in a lag phase, which may precede an exponential phase exhibiting rapid cell grow th and division. The bacteria may then enter a stationary phase, where growth may plateau due to nutrient depletion and / or toxin accumulation. Finally, the bacteria may enter a death phase and cell lysis may occur due to severe nutrient limitation or toxin accumulation. In various embodiments, one or more biomineralizing agents may exhibit the bacterial growth curve within a carrier, within a composition, and / or within concrete.

[0075] With reference to FIG. 6, exemplary growth curves for L. sphaericus inoculated in various culture media are illustrated. The culture media shown include milk extract 601, yeast extract 602, meat extract 603, beef extract 604, and peptone 605. The growth curve cultured in yeast extract is fitted under varying constraints, including fit one 606, fit two 607, and fit three 608. As illustrated by fits one 606, two 607, and three 608, y determines the maximum concentration of bacteria while a and rmdetermine the shape of the curve. Bacterial growth may follow- the formulaacterial° [Bacteria] — [Bacteria] o can °[Bacteria]0- [Bacteria]7 L Jrepresent the initial bacteria concentration, and So can represent the initial nutrient concentration. In an exemplary- embodiment, a composition described herein may be fit by a = 60. rm= 4, and y = 0.2.

[0076] With reference to FIG. 7, exemplary ureolysis reaction curves according to various initial urea concentrations are illustrated. The initial concentrations of urea illustrated are 15mM 701, 50mM 702, 80mM 703, 150mM 704, 200mM 705, 250mM 706, and 300mM 707. As illustrated, the urea decomposition speed may accelerate as the initial urea concentration increases (e.g., electric conductivity rises more quickly). With reference to FIG. 8, illustrates the relationship between electrical conductivity and the hydrolyzed urea concentration is illustrated. The Appelo theoretical model 801 and the McClesky theoretical model 802 are shown. With reference to FIG. 9, the hydrolyzed urea concentrations of the curves of FIG. 7 are illustrated. The curves are labeled by initial urea concentration 15mM 901,50mM 902, 80mM 903, 150mM 904, 200mM 905, 250mM 906, and 300mM 907. As illustrated, the trend remains similar to that illustrated in FIG. 7 (e.g., the hydrolyzed urea concentration may rise more quickly for a higher initial urea concentration). With reference to FIG. 10, initial ureolysis rates for the initial urea concentrations of FIG. 7 are illustrated. The curves are labeled by initial urea concentration 15mM 1001, 50mM 1002, 80mM 1003, 150mM 1004, 200mM 1005, 250mM 1006. and 300mM 1007. As illustrated, a greater initial urea concentration may result in a greater initial ureolysis rate. The rate of ureolysis may decline over time. With reference to FIG. 11, the initial urea hydrolysis rate versus the initial urea concentration curve 1101 determined by the data of FIGs. 7-10 is illustrated.

[0077] With reference to FIG. 12, exemplary microbial induced calcium carbonate production (MICCP) reactions and the resultant biomass are illustrated. A number of exemplary reactions 1210 were performed. The biomass generated 1211, (e.g.. calcium carbonate), by the reactions is shown. The centrifuged biomass 1212 and the dried biomass 1213 are shown. With reference to FIG. 13, exemplar}' obtained biomass versus time curves are illustrated. The experimentally obtained biomass 1301 from a first set of exemplary' reactions 1210 and the experimentally obtained biomass 1302 from a second set of exemplary reactions 1210 are shown. The rectangle illustrates the lag phase, also known as the stationary phase, with reference to FIG. 5.

[0078] With reference to FIG. 14, exemplary concentration curves for urea. CCh2-. Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP in a urea-limited environment are illustrated. The urea concentration 1401, the carbonate ion concentration 1402, the calcium ion concentration 1403, the ammonia concentration 1404, the biomineralizing agent concentration 1405, and the calcium carbonate concentration 1406 are shown. As the urea concentration 1401 is depleted, the calcium carbonate concentration plateaus.

[0079] Turning ahead to FIG. 17, exemplary concentration curves for urea, CCh2", Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP in a biomineralizing agentlimited environment are illustrated. The urea concentration 1701, the carbonate ion concentration 1702, the calcium ion concentration 1703, the ammonia concentration 1704. the biomineralizing agent concentration 1705, and the calcium carbonate concentration 1706 are shown. For example, such an embodiment may result from a nutrient deficiency which may prevent biomineralizing agent concentration growth. As the biomineralizing agent concentration declines, the rate of MICCP decreases and the time required to reach equilibriumof the MICCP reaction increases. Equilibrium may be reached when a majority of the biomineralizing agents are inactivated and the urea concentration 1701 is depleted.

[0080] With reference to FIG. 15, exemplary concentration curves in a solution for carbonic acid, bicarbonate, and carbonate ions versus the pH of the solution are illustrated. As the environment’s pH level increases, a greater amount of carbonic acid 1501 is converted to bicarbonate ions 1502, and as the pH level increases further, a greater amount of carbonic acid 1501 and bicarbonate ions 1502 are converted into carbonate ions 1503. With reference to FIG. 16, an exemplary pH curve 1601 for a solution during ammonia ionization in the MICCP reaction is illustrated. Hydroxide ions may be released by ammonia ionization, increasing the pH of the environment. In the illustrated exemplary embodiment, the urea was fully decomposed after 40 hours, where the pH reached a steady value of 11.3.

[0081] With reference to FIG. 18, an exemplary embodiment of a self-healing concrete comprising one or more vascular channels is illustrated. A concrete material 1810 may have one or more channels 1820 therethrough. Each channel 1820 may have an inlet 1830 and an outlet 1840. The one or more channels 1820 may share one or more common inlets 1830 and / or common outlets 1840. The concrete material 1810 may form one or more cracks 1850, for example due to one or more forces 1860 on concrete material 1810. One or more compositions as described herein may be flowed through one or more channels 1820. When a crack 1850 reaches a channel 1820, the composition may flow into the crack 1850 and may cause a repair of the crack 1850. An exemplary composition for flowing through channel 1820 may include one or more of one or more biomineralizing agents, urea, calcium ions, and / or nutrients.

[0082] Turning ahead to FIG. 19, exemplary concentration curves for urea, CO?2-. Ca2+, NH3, biomineralizing agents, and calcium carbonate during MICCP at a specific location are illustrated. The location may be an initial application location for a composition to the concrete. The urea concentration 1901. the carbonate ion concentration 1902. the calcium ion concentration 1903, the ammonia concentration 1904, the biomineralizing agent concentration 1905, and the calcium carbonate concentration 1906 are illustrated. The biomineralizing agent concentration 1905 grows rapidly due to a high initial nutrient concentration, which may result in a greater rate of MICCP. The chemicals and biomass generated at the initial application location may be distributed through a defect and / or a crack in the concrete during the repair process, such as by advection and / or dispersion.

[0083] With reference to FIG. 20A, exemplary concentrations of biomineralizing agents in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The biomineralizing agent concentration as a function of distance at 16 hours 2001, 32 hours 2002, 48 hours 2003, 64 hours 2004, 80 hours 2005, and 96 hours 2006 are shown. As illustrated, the concentration of the biomineralizing agent increases over time.

[0084] With reference to FIG. 20B, exemplar}' concentrations of urea in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The urea concentration as a function of distance at 16 hours 2011, 32 hours 2012, 48 hours 2013, 64 hours 2014, 80 hours 2015, and 96 hours 2016 are shown. As illustrated, the concentration of urea decreases over time.

[0085] With reference to FIG. 20C, exemplar}' concentrations of NH3 in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The NH3 concentration as a function of distance at 16 hours 2021, 32 hours 2022, 48 hours 2023, 64 hours 2024, 80 hours 2025, and 96 hours 2026 are shown. As illustrated, the concentration ofNFh increases over time.

[0086] With reference to FIG. 20D, exemplary concentrations of COs2' in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The COs2' concentration as a function of distance at 16 hours 2031, 32 hours 2032, 48 hours 2033. 64 hours 2034, 80 hours 2035, and 96 hours 2036 are shown. As illustrated, the concentration of CO?2' decreases over time.

[0087] With reference to FIG. 20E, exemplar}' concentrations of Ca2+in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The Ca2+concentration as a function of distance at 16 hours 2041, 32 hours 2042, 48 hours 2043, 64 hours 2044, 80 hours 2045, and 96 hours 2046 are shown. As illustrated, the concentration of Ca2+decreases over time.

[0088] With reference to FIG. 20F, exemplar}’ concentrations of calcium carbonate in a crack of the concrete versus distance from an initial application location after varying amounts of time are illustrated. The calcium carbonate concentration as a function of distance at 16 hours 2051, 32 hours 2052, 48 hours 2053, 64 hours 2054, 80 hours 2055, and 96 hours 2056 are shown. As illustrated, the concentration of calcium carbonate increases over time.

[0089] With reference to FIG. 22, an exemplary schematic diagram of the mechanism for describing pH effects on enzymatic urea hydrolysis is illustrated. E represents the enzyme, S represents a substrate (i.e., urea), and P represents a product species (i.e., ammonia). The enzyme substrate complex EH S' can be shifted towards EH2S or ES2' impacting the various equilibrium constants.

[0090] With reference to FIG. 23A, biomineralizing agent concentration curves for varying y values are illustrated. As shown and discussed above, y affects the maximum concentration of the biomineralizing agent. Values of y are illustrated as 0.06 2301. 0. 13 2302, 0.20 2303, 0.27 2304, and 0.34 2305. With reference to FIG. 23B, biomineralizing agent concentration curves for varying a values are illustrated. As shown, a affects the time to the half max growth concentration. Values of a are illustrated as 20 2311, 40 2312, 60 2313, 80 2314, and 100 2315. With reference to FIG. 23C, biomineralizing agent concentration curves for varying rmvalues are illustrated. As shown, rmaffects the overall growth rate of the biomineralizing agent concentration (i.e., the slope of the growth curve). Values of rmare illustrated as 1 2321, 2 2322, 4 2323, 6 2324, and 7 2325. Altering the value of y, a, and / or rmmay thus lead to different simulation results after data fitting. Vary ing ty pes of concrete may be represented by varying values for y, a, and / or rm. When forming a composition for concrete repair or performing a method for concrete repair, values for y, a, and / or rmmay be determined to prepare an effective composition or to use an effective method for the specific t pe and / or composition of concrete to be repaired.

[0091] With reference to FIG. 24, an exemplary' equivalent material representation of a damaged concrete material after MICCP healing is illustrated. In the illustrated embodiment, 1-d represents an undamaged portion of the concrete, whereas d represents a damaged portion of the concrete. Section d has a crack illustrated therethrough. Section ha represents a portion of the concrete that has been repaired by the MICCP repair process. Because the repaired material (i.e., the MICCP generated material) may have the same properties as the original concrete material, when ha = d, indicating that the entire damaged area has been repaired, the concrete may have the same structural properties as the original, undamaged concrete. In this manner, the concrete may be restored to the full value of its original strength.

[0092] With reference to FIG. 25, an exemplary schematic diagram for self-repair in concrete structures by vascularization is illustrated. The process may begin with the formation and / or existence of undersurface cracks 2510. A channel 2520 may be formed in the concrete having undersurface cracks 2510. In this manner, a vasculature architecture may be created,where the various undersurface cracks 2510 are connected by channel 2520. A composition as described herein may be applied to the channel 2530, such as by injection. The channel may deliver the composition to the undersurface cracks 2510. The composition may then cause repair of the concrete and / or the undersurface cracks 2510, resulting in a repaired concrete 2540.

[0093] With reference to FIG. 26, an exemplary process for self-repair of concrete is illustrated. In the illustrated embodiment, concrete 2610 has a surface crack 2620. A channel 2630 is formed in concrete 2610. The channel may intersect with and / or be adjacent to and / or be in fluid communication with the crack 2620. A composition as described herein may be applied to the channel 2640. The composition may cause repair of the concrete and / or the surface crack 2620, resulting in a repaired concrete.

[0094] With reference to FIG. 27, exemplary distributions of a carrier in damaged concrete and having a channel formed therein are illustrated. On the left, an illustrated embodiment having a 0.2mm crack in the concrete and a channel formed therein is illustrated. A carrier is shown applied to the concrete at 20° C 2701, 40° C 2702, and 60° C 2703. The area of carrier distribution within the damaged concrete is shown, being 96.28% in embodiment 2701, 95.25% in embodiment 2702, and 95.54% in embodiment 2703. On the right, an illustrated embodiment having a 0.8mm crack in the concrete and a channel formed therein is illustrated. A carrier is shown applied to the concrete at 20° C 2711, 40° C 2712. and 60° C 2713. The area of carrier distribution within the damaged concrete is shown, being 96.10% in embodiment 2711, 96.23% in embodiment 2712, and 97.15% in embodiment 2713. The channel formed in the concrete sample may facilitate the transport of a carrier and / or a composition in the crack. For example, the channel may enable more efficient integration depth for the composition in the concrete and / or better distribution of the composition in the concrete.

[0095] With reference to FIG. 28, an exemplary concrete sample having a crack and a channel formed therein are illustrated. A top view of the concrete sample 2810 is shown. The concrete sample 2810 has a crack 2820 and a channel 2830 formed intersecting with the crack 2820. A composition 2840, as described herein, has been provided in the channel 2830 and has flowed to crack 2820.

[0096] With reference to FIG. 29, an exemplar)’ microscopic view of a carrier containing one or more biomineralizing agents applied to a concrete sample having a crack and a channel formed therein is illustrated. The exemplary concrete sample 2910 has a 0.8mm crackand a channel 2920 formed intersection with the crack. The arrows in the top section 2930, the middle section 2940, and the bottom section 2950 of the concrete sample 2910 illustrate the presence of the one or more biomineralizing agents, which have dispersed through the concrete 2910. A control sample 2960, where pure 2% sodium alginate was provided to the channel rather than a composition described herein, is illustrated. As shown, there are no indications of one or more biomineralizing agents within the control sample 2960.

[0097] With reference to FIG. 30A, an exemplary thermogravimetric curve showing weight loss (%) in a reference concrete as a function of temperature 3010 is illustrated. Exemplary weight loss curves for calcium acetate 301 1, the reference concrete after 7 days 3012, the reference concrete after 14 days 3013, the reference concrete after 28 days 3014 are shown. A temperature region for decomposition of calcium acetate 3015 and a temperature region for decomposition of calcium carbonate 3016 are shown. With reference to FIG. 30B, an exemplary thermogravimetric curve showing weight loss (%) in concrete subjected to MICCP as a function of temperature 3020 is illustrated. Exemplary weight loss curves for calcium acetate 3021, the reference concrete after 7 days 3022, the reference concrete after 14 days 3023, the reference concrete after 28 days 3024 are shown. A temperature region for decomposition of calcium acetate 3025 and a temperature region for decomposition of calcium carbonate 3026 are shown.

[0098] With reference to FIG. 31 A. an exemplary thermogravimetric analysis of concrete samples providing the mg of biological calcium carbonate collected per mg of dried powder collected for varying time periods after MICCP is illustrated. Collections are illustrated at 7 days 3101, 14 days 3102, and 28 days 3103. The biological calcium carbonate collected 3120 is compared to the miscellaneous matter collected 3110, which may include moisture and / or nutrients. The ratio of biological calcium carbonate 3120 collected to miscellaneous matter 3110 collected remained relatively steady, indicating that the MICCP process is at equilibrium. With reference to FIG. 3 IB, an exemplary thermogravimetric analysis of concrete samples providing a mass of biological calcium carbonate collected for varying time periods after MICCP is illustrated. Collections are shown at 7 days 3104, 14 days 3105, and 28 days 3106. As shown, the total mass of biological calcium carbonate collected progressively increases as time passes.

[0099] With reference to FIG. 32A, a number of exemplary x-ray diffraction analyses of concrete for varying time periods are illustrated. X-ray diffraction analyses of control samples of concrete at 7 days 3201. 14 days 3202, and 28 days 3203 predominantly indicatethe presence of calcite. With reference to FIG. 32B, a number of exemplary x-ray diffraction analyses of concrete for varying time periods subjected to MICCP are illustrated. X-ray diffraction analyses of concrete subjected to MICCP at 7 days 3204, 14 days 3205, and 28 days 3206 indicate the presence of both calcite and vaterite.

[0100] With reference to FIG. 33 A, an exemplary concrete sample 331 having bacterial nanocellulose 3320 applied to a crack is illustrated. The bacterial nanocellulose 3320 may be applied by laying it on the crack and / or forming a pellicle and applying the pellicle to the crack. The bacterial nanocellulose may be applied to the concrete by any method of application described herein. With reference to FIG. 33B, the exemplary embodiment of FIG. 33A after a period of time is illustrated. The bacterial nanocellulose 3320 is distributed within the crack and / or the concrete 3310 and has begun to repair the concrete 3310. Any of the compositions described herein, including for example the illustrated bacterial nanocellulose 3320, may be formed ex-situ and applied to the concrete 3310.

[0101] With reference to FIG. 21, treated concrete samples 3410 and control concrete samples 3420 are illustrated. Treated concrete samples 3410 have been treated with a composition described herein. Each of treated concrete samples 3410 and control concrete samples 3420 have a crack. As shown, control concrete samples 3420 retain their crack and / or damage. Concrete samples 3411 and concrete sample 3412 are two of treated concrete samples 3410. Concrete sample 3411 was treated with an exemplary composition comprising agar. PGA, and enzy mes. As shown, the crack in concrete sample 3411 was substantially repaired by the exemplary' composition. Concrete sample 3412 was treated with an exemplary' composition comprising agar, PGA, and bacteria. As shown, the crack in concrete sample 3412 was substantially repaired by the exemplary composition.

[0102] With reference to FIG. 34A, an exemplary’ damaged concrete sample 3510 treated with an in-situ formed composition 3511 including bacterial nanocellulose and additives is illustrated. A top view 3512 of concrete sample 3510 and a cross-section 3513 of concrete sample 3510 are provided. As shown, the crack in concrete sample 3510 was substantially repaired by composition 3511.

[0103] With reference to FIG. 34B, an exemplary' damaged concrete sample 3520 treated with an in-situ formed composition 3521 including bacterial nanocellulose, additives, and enzymes is illustrated. A top view 3522 of concrete sample 3520 and a cross-section 3523of concrete sample 3520 are provided. As shown, the crack in concrete sample 3520 was substantially repaired by composition 3521.

[0104] For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of some features and techniques may be omitted to avoid unnecessarily obscuring the present disclosure. Additionally, elements in the drawing figures are not necessarily draw n to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present disclosure. The same reference numerals in different figures denote the same elements.

[0105] The terms “first,” “second,” “third.” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, composition, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, composition, or apparatus. In some cases, the terms including, having, or comprising encompass consisting essentially of and consisting of.

[0106] The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the apparatus, methods, and / or articles of manufacture described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0107] The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements mechanically and / or otherwise. Two or more electrical elements may be electrically coupled together, but not be mechanically or otherwise coupled together. Coupling may be for any length of time. e.g.. permanent or semi -permanent or only for an instant. “Electrical coupling” and the like shouldbe broadly understood and include electrical coupling of all types. The absence of the word “removably,’7“removable.” and the like near the word “coupled,” and the like does not mean that the coupling, etc. in question is or is not removable.

[0108] As defined herein, two or more elements are “integral” if they are comprised of the same piece of material. As defined herein, two or more elements are “non-integral” if each is comprised of a different piece of material.

[0109] As defined herein, “approximately” can, in some embodiments, mean within plus or minus ten percent of the stated value. In other embodiments, “approximately” can mean within plus or minus five percent of the stated value. In further embodiments, “approximately” can mean within plus or minus three percent of the stated value. In yet other embodiments, “approximately” can mean within plus or minus one percent of the stated value.

[0110] Although compositions and methods for concrete repair have been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the spirit or scope of the disclosure. Accordingly, the disclosure of embodiments is intended to be illustrative of the scope of the disclosure and is not intended to be limiting. It is intended that the scope of the disclosure shall be limited only to the extent required by the appended claims. For example, to one of ordinary skill in the art, it will be readily apparent that any element of FIGs. 1-35 may be modified, and that the foregoing discussion of certain of these embodiments does not necessarily represent a complete description of all possible embodiments. For example, one or more of the procedures, processes, or activities of FIG. 1 may include different procedures, processes, and / or activities and be performed by many different modules, in many different orders.[OHl] Benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are stated in such claim.

Claims

CLAIMSWhat is claimed is:

1. A composition for concrete repair, comprising: a carrier; one or more encapsulants; one or more biomineralizing agents encapsulated within the one or more encapsulants; and one or more additives within the earner.

2. The composition of claim 1, wherein the carrier comprises one or more of a polymer or a hydrogel.

3. The composition of claim 2, wherein the hydrogel comprises one or more of agar, sodium alginate, or a gelatin.

4. The composition of claim 1, wherein the one or more biomineralizing agents comprise bacteria.

5. The composition of claim 4, wherein the bacteria comprises one or more of Sporosarcina pasteurii, Lysinibacillus sphaericus, or Komagataeibacter xylinus.

6. The composition of claim 1, wherein the one or more biomineralizing agents comprise enzymes.

7. The composition of claim 6, wherein the enzymes comprise urease.

8. The composition of claim 1, wherein the one or more encapsulants comprise one or more of Lysinibacillus sphaericus, sodium alginate, calcium acetate, or nutrient media.

9. The composition of claim 1, wherein the one or more encapsulants comprise one or more of spray dried encapsulants, emulsion encapsulants, or inverse suspension encapsulants.

10. The composition of claim 1, wherein the one or more additives comprise one or more of fibers or grains.

11. The composition of claim 10, wherein the fibers comprise at least one of flax fibers or basalt fibers.

12. A composition for concrete repair, comprising: a gel comprising bacterial nanocellulose: and a biomineralizing agent.

13. A method of repairing concrete, the method comprising: providing the composition of claim 1; and applying the composition to the concrete.

14. The method of claim 13, wherein the step of applying comprises injecting the composition into the concrete.

15. The method of claim 13, wherein the step of applying comprises providing a viscous paste within a defect of the concrete.

16. The method of claim 13, wherein the step of applying comprises spraying.

17. The method of claim 13, wherein the step of applying comprises laying a film comprising the composition on the concrete.

18. The method of claim 13, wherein the step of applying comprises: forming a channel within the concrete; and injecting the composition into the channel.

19. The method of claim 18, wherein the carrier comprises sodium alginate and wherein the one or more biomineralizing agents comprises Lysinibacillus sphaericus.

20. The method of claim 13, further comprising wetting the concrete prior to applying the composition.

21. A method of repairing concrete, the method comprising: forming a bacterial nanocellulose pellicle; and applying the bacterial nanocellulose pellicle to the concrete.

22. The method of claim 21, wherein the bacterial nanocellulose pellicle comprises one or more biomineralizing agents.

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