19 results about "Pozzolanic activity" patented technology

The application discloses a kind of anti-freezing concrete and preparation method of multi-generation recycling, the concrete is by following raw material is formed according to weight parts: cement 405~418 parts, nano silicon dioxide 8~20 parts, river sand 680~735 parts, recycled coarse aggregate 865~890 parts, water 168~194 parts, polycarboxylate superplasticizer 2.2 parts and alkyl benzene sulfonate air entraining agent 0.05~0.1 parts.The application uses nano silicon dioxide as raw material, which has high specific surface area and pozzolanic activity, and the alkyl benzene sulfonate air entraining agent reduces the aggregation of nano silicon dioxide, not only promotes its uniform dispersion in concrete, but also makes the pore distribution in concrete uniform, thereby improving the mechanical properties and frost resistance of concrete, and the second generation and third generation recycled coarse aggregate obtained by crushing after 400 freeze-thaw cycles can be used in structural concrete in cold regions, greatly reducing material waste and environmental pollution.

The invention belongs to the technical field of industrial solid waste recycling and filling materials, and particularly discloses a method for improving pozzolanic activity of water-quenched copper slag through synergistic modification of magnetic separation iron removal, which comprises the following steps: adding CaO into molten copper slag discharged in a copper smelting process, uniformly mixing, reacting in an oxygen-containing atmosphere, and then carrying out water quenching and quenching to obtain the pozzolanic activity of the water-quenched copper slag. Modified copper slag particles are obtained; the modified copper slag particles are subjected to wet grinding and drying, and modified copper slag powder is obtained; and the modified copper slag powder is subjected to magnetic separation, and magnetic iron ore concentrate and non-magnetic tailings are obtained. The prepared non-magnetic tailings replace part of cement to prepare the auxiliary cementing material with high pozzolanic activity. Through the synergistic effect of CaO modification and a magnetic separation iron removal process, the pozzolanic activity of the water-quenched copper slag is remarkably improved. The method is simple and convenient in process, the high value-added application way of the water-quenched copper slag is effectively widened, the resource utilization rate is increased, and the method has important significance on promoting comprehensive utilization of solid waste and environmental protection.

The invention relates to the technical field of cement and concrete, in particular to a Bayer process red mud volcanic ash activity evaluation method which comprises the following steps: calcining Bayer process red mud to be detected to obtain calcined Bayer process red mud; the polymerization degree of the calcined Bayer process red mud is measured by adopting Fourier transform infrared spectroscopy, the polymerization degree of the Bayer process red mud is in negative correlation with the activity, the pozzolanic activity of the Bayer process red mud is evaluated by measuring the polymerization degree, and the pozzolanic activity of the Bayer process red mud is evaluated by adopting the Fourier transform infrared spectroscopy to measure the polymerization degree of the Bayer process red mud. The polymerization degree of the red mud is reduced along with the increase of the volcanic ash activity and is in negative correlation, and the compressive strength and the dissolution solubility of Si + Al are in positive correlation with the volcanic ash activity of the red mud.

The application discloses a kind of full solid waste mine repair soil and preparation method thereof, it is related to soil repair technical field, the full solid waste mine repair soil includes the following weight content of raw material composition: titanium gypsum 50~80%, converter steel slag 15~30%, titanium extraction tailings 5~15%, sintering machine head ash 0~5%.In the application, titanium gypsum contains fine-grained calcium sulfate dihydrate, iron hydroxide, etc., has good water retention effect;Converter steel slag contains P, can provide phosphorus fertilizer effect for soil, and the alkalinity of steel slag can adjust the acidity and alkalinity of soil;Secondly, steel slag and titanium extraction tailings jointly act, play the role of solidifying soil and preventing water and soil loss;The pozzolanic activity of titanium extraction tailings is good, and forms strength matrix with steel slag, can solidify soil;Sintering machine head ash contains K, can provide potassium fertilizer effect for soil.

The invention relates to the field of building materials, and provides a volcanic ash activity evaluation method suitable for a solid waste auxiliary cementing material, and the method comprises the following steps: preparing a solid waste auxiliary cementing material sample; performing Fourier transform infrared spectrum detection on the sample under a specific wave number; performing baseline correction on a solid waste infrared spectrum result; carrying out Gaussian deconvolution processing on the Fourier transform infrared spectrum after baseline correction under a specific wave number; then, third-order derivative peak-dividing fitting processing is adopted, and a fitting peak with the site unchanged along with automatic fitting is fixed at each of five specific wave number sites to represent infrared absorption peaks of Q0, Q1, Q2, Q3 and Q4; calculating the tetrahedral polymerization degree of the solid waste powder Si (Al) O4 by using the peak areas of Q0, Q1, Q2, Q3 and Q4; and calculating the volcanic ash activity. The limitation that a traditional strength method depends on long-age hydration reaction is broken through, direct conversion from structural characteristics to activity is achieved, traditional 28-day curing age test is shortened to be completed within 2 hours, the construction period is remarkably shortened, and the detection efficiency is greatly improved.

The invention discloses composite superfine slag powder for concrete and a preparation method of the composite superfine slag powder, and belongs to the field of superfine slag powder. Comprising the following raw materials in parts by mass: 80-90 parts of granulated blast furnace slag, 4-10 parts of silica fume and 2-5 parts of a stabilizer, and the stabilizer contains 10-30wt% of cerium oxide. The silica fume has higher pozzolanic activity, can accelerate an early hydration reaction, stimulates potential hydraulicity of the superfine slag powder, and can improve the compressive strength and stability of the concrete. By adding the stabilizer, phase change of beta-C2S in the slag can be inhibited, cerium oxide can fill lattice defects, hinder crystal nucleus reconstruction, inhibit conversion of beta-C2S into gamma-C2S without activity and induce beta-C2S to form a more stable structure, and by increasing the stability and content of beta-C2S in the slag, the stability and content of the gamma-C2S in the slag can be improved. The gel activity and the active substance content of the superfine slag powder are further improved, and the superfine slag powder with high activity index and stable performance is obtained.

The invention belongs to the technical field of cement, and discloses a method for rapidly testing pozzolanic activity of a pozzolanic material, which comprises the following steps: step 1, preparing a simulated pore solution of cement paste; 2, respectively adding samples of a plurality of types of pozzolanic materials into the corresponding simulated pore solutions, and dispersing to obtain corresponding sample suspensions; 3, quantitatively taking the sample suspension of each sample, and carrying out Zeta potential test; 4, fitting the Zeta potential of each sample and the corresponding intensity activity index to obtain a fitting curve; and step 5, taking a sample to be tested, testing the Zeta potential of the sample to be tested according to the process from the step 1 to the step 3, and determining the strength activity index of the sample to be tested based on the fitted curve. According to the invention, the test is rapid, simple and convenient, the detection time is greatly reduced, and the interference of human factors is avoided.

This invention provides a mixed calcium-enriched thermally activated loess and its preparation method and application, modified loess cement-based cementitious materials and their application, and modified loess cement-based cementitious hydration materials and their application, relating to the field of coal mine grouting and water-retaining mining technology. This invention mixes loess with a calcium-enriching agent and calcines it to obtain mixed calcium-enriched thermally activated loess; the calcium-enriching agent includes dolomite and soda ash; the mass ratio of loess to calcium-enriching agent is 1.5–2.5:1; the calcination temperature is 1000–1100℃. This invention utilizes dolomite and soda ash to calcium-enrich and modify loess, and controls the calcination temperature and the amount of calcium-enriching agent, greatly improving the pozzolanic activity of loess, thereby enhancing the hydration reaction activity of modified loess in the preparation of cement-based grouting materials. The mixed calcium-enriched thermally activated loess provided by this invention has excellent application prospects in mine water-retaining grouting.

This invention discloses a high-performance concrete containing modified red brick powder and its preparation method, belonging to the field of building materials technology. The high-performance concrete is prepared from the following raw materials in parts by weight: 280-380 parts cement, 60-160 parts modified red brick powder, 1050-1250 parts coarse aggregate, 650-850 parts fine aggregate, 140-190 parts water, and 6-12 parts water-reducing agent. The modified red brick powder is obtained by pre-treating waste red bricks and then soaking, grinding, and drying them with a sodium silicate-alumina sulfate composite modifier. This invention utilizes the synergistic effect of sodium silicate-alumina sulfate composite modifier to increase the pozzolanic activity index of red brick powder to 90%-95%. The resulting concrete exhibits a 28-day compressive strength of over 56 MPa, a permeability grade of P10-P12, a freeze-thaw resistance grade of F250-F300, and excellent resistance to carbonation and chloride ion penetration. Even under low-temperature curing conditions of 10±2℃, the 42-day compressive strength still reaches 57.8 MPa. Simultaneously, it achieves the resource utilization of waste red bricks, reduces concrete production costs, and aligns with the trend of green building.

The invention provides a method for preparing building self-heat-preservation wall concrete from waste concrete and waste brick powder, and relates to the technical field of building facilities, the method comprises the following steps: raw material pretreatment, ingredient preparation, segmented stirring and molding maintenance; the raw material pretreatment comprises the steps of carrying out crushing, spray grinding and steam pre-wetting treatment on waste concrete to obtain modified recycled aggregate, and carrying out grinding, calcination activation and surface modification treatment on waste brick powder to obtain activated waste brick powder; according to the step of segmented stirring, aggregate dry stirring, cementing material dry stirring and wet stirring are sequentially carried out in a forced stirring machine, waste brick powder is subjected to a dual process of calcination activation and silane coupling agent modification, the volcanic ash activity of the waste brick powder is improved by 30% or above through calcination, chemical bridging is formed between the powder and a cement matrix through a silane coupling agent, and then the waste brick powder is subjected to wet stirring. The conversion of the waste brick powder from an inert filler to an active gelling component is realized, so that the strength and durability are synchronously improved when the waste concrete and the waste brick are compositely utilized.

The application discloses a method for activating coal gangue by using steel slag waste heat and in-situ carbon fixation, which utilizes the waste heat of high-temperature molten steel slag, activates coal gangue by means of a steel slag heat sweating device system, so that the coal gangue obtains higher pozzolanic activity, meanwhile, the steel slag reacts with CO2 to generate stable carbonate, captures CO2 released in the heat activation process, and realizes permanent carbon sequestration. The application effectively utilizes the heat of hot steel slag discharged from a steel smelting furnace, activates coal gangue, and at the same time, the steel slag generates a carbonation reaction, thereby improving the heat recovery rate in the steel slag cooling process; through the coupling effect of heat activation and carbonation, the steel slag is used to capture CO2 generated in the coal gangue activation process, thereby realizing the synergistic effect of coal gangue-steel slag activation and carbon fixation, providing a new idea for the utilization of coal-based solid waste; the coal gangue is used to prepare high pozzolanic activity materials, and the stability of the steel slag is improved, so that the steel slag is convenient for subsequent building material utilization, and the resource utilization rate of the steel slag is increased.

A concrete composition, the concrete composition comprising: cementitious material; carbonaceous material; reactive silica; and insoluble silicon. The concrete composition may comprise a pozzolan. The pozzolan may have pozzolanic activity. A concrete composition comprising: cementitious material; and carbonaceous material, wherein at least a portion of the carbonaceous material has no pozzolanic activity. The carbonaceous material may comprise biochar. A method of making a concrete composition, the method comprising: milling a carbonaceous material to form a milled carbonaceous material, wherein at least a portion of the milled carbonaceous material has no pozzolanic activity; combining the milled carbonaceous material with a cementitious material; contacting the cementitious material with an aggregate; contacting the cementitious material with water; and subjecting the carbonaceous material to pyrolysis.

This invention belongs to the field of ceramsite preparation technology, and provides a non-fired ceramsite made from coal gasification slag and its preparation method. The raw materials for the non-fired ceramsite made from coal gasification slag are a matrix of non-fired ceramsite made from coal gasification slag, a binder, an alkali activator, a water-reducing agent, and water. The matrix of the non-fired ceramsite made from coal gasification slag is composed of the following components by mass percentage: 50-60% coal gasification slag, 15-30% fly ash, 5-15% river sand, and 15-20% cement; the amounts of binder and alkali activator are 7-10% and 0-3% of the mass of the matrix of non-fired ceramsite made from coal gasification slag, respectively. This invention utilizes the low apparent density and pozzolanic activity of coal gasification slag raw materials, aiming to prepare non-fired ceramsite with low bulk density, low water absorption, and high strength by adjusting the raw material ratio and the amount of alkali activator, without the need for pore-forming agents or surface treatment, while ensuring that the coal gasification slag content is ≥50% and the cement content is ≤20%.

A method for thermal activation of coal gangue and in-situ carbon fixation utilizing waste heat from steel slag is disclosed. By utilizing waste heat from high-temperature molten steel slag, coal gangue is activated to a high pozzolanic activity utilizing the system temperature of a steel slag hot-steaming device, and meanwhile, the CO2 released in the thermal activation process is captured utilizing the reaction of steel slag with CO2 to generate stable carbonates, thus achieving permanent carbon sequestration. The present disclosure effectively uses the heat from the hot steel slag discharged from the steelmaking furnace in such a way that the coal gangue is activated while the steel slag undergoes a carbonation reaction, resulting in an increased heat recovery rate during the cooling process of the steel slag.

The present application relates to the field of inorganic non-metallic materials, and more particularly to a micro-silicon powder, a preparation method and applications thereof. The preparation method comprises: heat treatment, screening, water washing and sedimentation, and / or silane coupling agent modification of the industrial raw micro-silicon powder. The present application innovatively combines precise temperature control heat treatment, green physical purification and targeted chemical modification, and simultaneously realizes deep impurity removal (carbon and soluble alkali metals) and surface hydrophobic modification on the premise of preserving the key spherical morphology and pozzolanic activity of the micro-silicon powder.

This invention discloses a method for surface modification of ceramic powder and its application in ultra-high strength concrete, belonging to the field of building materials technology. The modification method uses nano-calcium carbonate, HPMC, and KH550 as composite modifiers, and through dry mechanical activation by a turbine propeller, forms a modified ceramic powder with a "filling-dispersion-bonding" coating layer. The modified ceramic powder achieves a 28-day pozzolanic activity index of 85%–95%. Replacing 10%–20% of cement with this modified ceramic powder, and combining it with an aggregate system of quartz sand and ceramic waste, UHPC is prepared. After steam curing at 60–70℃, the 28-day compressive strength is ≥170MPa, the 60-day strength reaches 190MPa, and the chloride ion penetration resistance coefficient is ≤5×10⁻⁶. ‑13 m 2 The process can dispose of 150-200 kg of ceramic waste per cubic meter per second. This invention features a simple process that achieves synergy between high-value utilization of construction solid waste and large-scale UHPC (Ultra-High-Performance Computing), making it suitable for applications in bridges, high-rise buildings, and other fields.

The invention discloses a lithium slag composite cementing material for a rapid repair material as well as a preparation method and application of the lithium slag composite cementing material. The lithium slag composite cementing material is prepared from Portland cement, sulphoaluminate cement clinker, lithium slag powder, fibers, a water reducing agent and redispersible latex powder according to a specific mass percent. Gypsum in the lithium slag is rapidly consumed through the sulphoaluminate cement, inhibition of the gypsum on the volcanic ash activity of the lithium slag is relieved, meanwhile, the Portland cement provides an alkaline environment to excite the activity of the lithium slag, C-S-H gel is generated, and the middle and later strength is remarkably improved. The material has the characteristics of early strength, rapid hardening, micro expansion, low shrinkage, high bonding strength, excellent durability and the like, is suitable for rapid repair engineering of pavements, bridges, terraces and the like, and has good economic benefits and environmental protection benefits.

The invention provides a preparation method of multi-source solid waste foundation filling aggregate improved based on an MICP technology, and belongs to the technical field of filling aggregate. Firstly, aggregate, pretreated polyethylene fiber, a mixture of slag and coal gangue, fly ash and double gypsum serve as raw materials to prepare a foundation base layer, the aggregate serves as a base layer framework to provide supporting strength, the surface of the polyethylene fiber is rough and is of a porous structure, and rich attachment sites can be provided for bacillus pasteurii; loss of microorganisms along with treatment liquid is reduced; the slag and the coal gangue need to be ground, so that aggregate gaps can be filled, and the compactness of a base layer is improved; the spherical particle morphology of the fly ash can improve the workability of the mixture, and meanwhile, the activity of the volcanic ash and the surface of the aggregate form a cementation effect. According to the invention, through MICP technical treatment, the problem of foundation base cracks is effectively repaired and solved.

The invention relates to the technical field of building materials, in particular to an ultrasonic dispersion silica fume reinforced LC3 cement-based material and a preparation method thereof.The preparation method comprises the steps that before silica fume is mixed with dry material components of an LC system, the silica fume is mixed with part of mixing water, pretreatment is conducted through the cavitation effect of ultrasonic waves, and then the silica fume and the dry material components are mixed; the silica fume aggregate is depolymerized into submicron monodisperse particles through synergistically optimized ultrasonic power and time parameters, and a high-dispersity silica fume suspension is obtained; and mixing the suspension liquid with a pre-mixed LCR (Liquid Chromatography) dry blend. According to the method, the risk that the silica fume aggregate is introduced into the system as a structural defect is fundamentally eliminated, so that the silica fume can give full play to the pozzolanic activity, micro-filling and nucleation effects of the silica fume; according to the prepared LCcement-based material, the early-stage compressive strength is remarkably improved, the later-stage strength loss caused by a conventional doping mode is effectively avoided, and the synergistic enhancement of the whole-age mechanical property is realized.