86 results about "Sulphate attack" patented technology

The invention relates to the technical field of building material modification, in particular to an anti-freeze thawing-sulfate composite modifier and application thereof in a water-stable base layer. In road engineering, a water-stable base layer often faces the problems of freeze-thaw cycle and sulfate erosion damage. The key point of the technical scheme of the invention is as follows: on the basis of the mass of cement, a composite modifier is composed of the following components in percentage by mass: 2%-5% of sodium sulfate, 0.02%-0.05% of sodium gluconate, 0.4%-0.6% of polypropylene fiber, 0.1%-0.2% of steel fiber, 1%-3% of butadiene styrene rubber emulsion, 0.05%-0.5% of sodium carboxymethyl cellulose, 0.05%-0.1% of triethanolamine, 0.1%-0.5% of naphthalene water reducer, 0.005%-0.02% of air entraining agent, 8%-10% of silica fume and the like. The composite modifier is mainly used for the water-stabilized base, can effectively improve the freeze-thaw resistance and sulfate erosion resistance of the water-stabilized base, and prolongs the service life of a road.

The invention discloses an anti-sulfate-attack preparation method of solid waste concrete, and relates to the technical field of building materials and civil engineering, the anti-sulfate-attack solid waste concrete is prepared from the following materials in parts by weight: 100 parts of cement, 30-50 parts of composite solid waste cementing material, fly ash, steel slag micro powder and coal gangue according to a given mass ratio, 60-80 parts of modified recycled aggregate; 0.05-0.1 wt% of sodium molybdate as an erosion inhibitor. According to the invention, solid waste activation-interface reconstruction-ion competition-structure self-healing is taken as a core, synchronous spanning of solid waste concrete in the dimensions of sulfate erosion resistance, resource consumption, construction convenience and the like is realized through multi-process collaboration, and the gelation potential of solid wastes such as fly ash and steel slag is accurately excited through microwave targeted activation, so that the construction efficiency is improved. And a dense microstructure is reconstructed by combining a nano-SiO2 induced crystallization technology, so that excellent mechanical properties are still ensured when the solid waste mixing amount exceeds 70%.

The invention discloses sulfate-erosion-resistant metakaolin-slag-based geopolymer concrete, belongs to the technical field of concrete, and aims to solve the problems that the corrosion resistance of traditional silicate concrete is ineffective and the adaptability of conventional alkali-activated concrete is insufficient in a special environment. The concrete comprises the following components in parts by weight: 60-90 parts of a cementing material, 120-170 parts of aggregate, 15-30 parts of a composite activator, 2-8 parts of a function regulator and the like, the cementing material is prepared from nano TiO2 / KH-550 composite modified metakaolin, slag and silica fume-coal gangue powder-HAP composite powder; the aggregate comprises modified limestone macadam (soaked and dried by a sodium dihydrogen phosphate solution) and river sand; the composite exciting agent comprises water glass, sodium hydroxide, sodium pyrophosphate, propylene glycol and the like; the function regulator comprises superfine fly ash, a naphthalene water reducer, HPMC (Hydroxy Propyl Methyl Cellulose) and boric acid. Through the synergistic effect of the components, the sulfate corrosion resistance, the mechanical property and the environmental adaptation performance of the concrete are improved, and the concrete is suitable for engineering construction under the service environment of high-concentration sulfate and the like.

The invention discloses a moss ecological brick and a preparation method thereof, and relates to the technical field of ecological restoration, the moss ecological brick comprises a moss gametophyte matrix and a brick body, the brick body comprises the following raw materials: a tailing composite material, metakaolin, an acid activator and water, and the tailing composite material comprises phosphate tailings and iron tailings. The phosphate tailings and the iron tailings can provide necessary phosphorus elements, other trace elements and the like for the growth of the moss, and the acid activator in the brick body not only can provide a weak acid environment to facilitate the good growth of the moss, but also can solve the problem of saltpetering of the brick body in the environment; the growth of the moss can effectively relieve sulfate erosion of the acid-activated material, and a good curing environment is provided for the acid-activated concrete brick body. Therefore, in the moss ecological brick provided by the invention, the acid-activated concrete brick body can supplement and promote the growth of moss.

The invention belongs to the technical field of building material and solid waste resource utilization, and relates to a high-durability and high-toughness slag powder-steel slag powder quaternary synergistic excitation-reinforcing agent and a preparation method of gel system mortar. The quaternary synergistic excitation-reinforcing agent comprises the following raw materials in parts by mass: 4-16 parts of sodium hydroxide, 79 parts of sodium silicate, 4-16 parts of aluminum sulfate and 60 parts of metakaolin, and the sum of the mass parts of the sodium hydroxide and the aluminum sulfate is 20. According to the quaternary synergistic excitation-reinforcing agent, sodium hydroxide and sodium silicate are used as main excitants, and aluminum sulfate serving as a function regulator and metakaolin serving as a high-activity aluminum-silicon source and a micro aggregate are introduced to serve as synergistic reinforcing components; the four components cooperate to jointly form an excitation-reinforcement composite system with high durability and high toughness; the sulfate erosion resistance, the chloride ion penetration resistance, the carbonization resistance, the toughness and the impact resistance of the slag powder-steel slag powder cementing system mortar are improved.

The invention discloses high-durability aluminoferrite cement-based self-compacting concrete and a preparation method thereof, and belongs to the technical field of maritime work concrete.The high-durability aluminoferrite cement-based self-compacting concrete is prepared from 60-70 parts of freeze-thaw-resistant clinker, 20-30 parts of chlorine-resistant steel slag micro powder, 8-13 parts of high-strength corrosion-resistant desulfurized gypsum, 0.8-1.3 parts of an additive, 88-124 parts of coarse aggregate, 76-116 parts of fine aggregate and 22-38 parts of water. According to the freeze-thaw-resistant clinker, the freezing resistance of concrete is enhanced by reducing the porosity and the pore diameter. The desulfurized gypsum subjected to crystal form regulation and control enhances the sulfate corrosion resistance of the concrete. The PAA / QCS-CA hydrogel enables the early strength of the concrete to be rapidly increased, accelerates the construction progress, and ensures that the airport pavement can be rapidly put into use. The high-strength corrosion-resistant desulfurized gypsum can promote early hydration of the cement and improve the early strength.

The present application belongs to the technical field of concrete, and discloses a method for evaluating the degradation grade of concrete aggregate caused by sulphate attack. The method comprises the following steps: first, preparing fine aggregate samples from the sulphur-containing aggregate to be evaluated; then, mixing the samples with cement and water to prepare mortar expansion rate test pieces and mortar flexural strength test pieces; next, testing the 84d expansion rate of the mortar expansion rate test pieces and the 84d flexural strength retention rate of the mortar flexural strength test pieces; finally, evaluating the grade according to the test results: if the 84d expansion rate is greater than 0.2%, the sulphate attack is determined to be strong; if the 84d expansion rate is less than or equal to 0.2% and the flexural strength retention rate is less than 80%, the sulphate attack is determined to be moderate; if the 84d expansion rate is less than or equal to 0.2% and the flexural strength retention rate is greater than or equal to 80%, the sulphate attack is determined to be weak. The present application solves the problem of the lack of a unified test method standard for sulphate attack on concrete aggregate, provides a complete test method, establishes an evaluation system for the damage grade of sulphate attack, and promotes the use of aggregate with excessive sulphur content.

Lime-based cement extender or cement replacement compositions and formulations, and associated systems and methods are disclosed herein. In some embodiments, a lime-based cement extender or cement replacement composition includes at least 5% by weight lime particles and at least 50% by weight pozzolan particles. In some embodiments, the pozzolan particles include silicon dioxide and aluminum oxide. In some embodiments, composition can be combined with admixtures and / or aggregates to produce a formulation. The formation can have at least 5.000 ppm soluble sulfate and an alumina: silica ratio of at least 0.2: 1. Methods of accelerating formation of calcium aluminum sulfates to avoid sulfate attacks during critical periods include producing a formulation with high aluminum oxide content, admixtures configured to accelerate certain chemical reactions, and omitting limestone. Methods of delaying formation of calcium aluminum sulfates to avoid sulfate attacks during critical periods include producing a formulation with admixtures configured to delay certain chemical reactions.

The invention relates to a method for preparing cement clinker from magnesium slag and carbide slag, and belongs to the technical field of cement materials.The cement clinker is prepared from carbide slag, modified magnesium slag, activated converter slag and coal gangue as main raw materials, the modified magnesium slag is an Mg3 (PO4) 2 protective layer formed by ball-milling modification of magnesium slag through a Mg (H2PO4) 2 aqueous solution and a ferulic acid ethanol solution, and the magnesium slag is a magnesium slag protective layer formed by ball-milling modification of activated converter slag and coal gangue. The activated converter slag is obtained by roasting and activating the converter slag and Na2CO3; the four raw materials are mixed according to a certain proportion, a Li2B4O7-CaF2 composite mineralizer is added for low-temperature calcination, a proper amount of SO2 is introduced to induce generation of a new three-phase system of gehlenite-dicalcium silicate-spinel, carbon emission can be effectively reduced, fuel energy consumption can be saved, and the obtained cement clinker has high early strength and can be widely applied to the field of cement materials. The early strength and the later strength stability are well balanced, cracking is not prone to occurring, and the sulfate corrosion resistance is excellent.

The invention discloses low-heat slag cement and a preparation method thereof. The cement is prepared from the following components in percentage by weight: 50%-70% of high belite Portland cement clinker, 20%-50% of active slag micropowder, 4%-6% of gypsum, 1%-5% of composite functional filler, 0.1%-1.0% of a construction performance regulator and 0.01%-0.1% of a grinding aid. The preparation method comprises the following steps: preparing the rapidly cooled high belite clinker; the slag and the sodium sulfate-triethanolamine composite exciting agent are jointly ground to prepare high-activity slag micro powder; all the components are jointly ground in proportion until the specific surface area is 300-400 m / kg, and the proportion of particles with the particle size of 3-30 microns is controlled to be larger than 70%. Through the synergistic effect of multiple components, low hydration heat (less than or equal to 230kJ / kg in 7 days), high early strength (more than or equal to 12MPa in 7 days) and high later strength (more than or equal to 32.5 MPa in 28 days) are realized at the same time, and the concrete has excellent chloride ion permeation resistance and sulfate attack resistance, is excellent in construction performance, and is particularly suitable for engineering construction of mass concrete and in a severe environment.

This invention discloses a method for predicting concrete strength based on surface color changes under sulfate attack. The steps are as follows: preparing several sets of standard concrete specimens; conducting sulfate attack experiments on the standard concrete specimens for different numbers of attacks; testing the compressive strength of the standard concrete specimens under different numbers of attacks; measuring the surface color of the standard concrete specimens after testing the compressive strength under different numbers of attacks and creating a standard color chart for concrete sulfate attack; establishing the correspondence between the content of corrosion products and the number of cycles; establishing a curve showing the relationship between surface color and total content of corrosion products; establishing a curve showing the relationship between corrosion products and compressive strength; and predicting the compressive strength of concrete in the field. This invention provides a short evaluation cycle, high accuracy, and avoids damage to the concrete structure.

The present application relates to the technical field of concrete, in particular to a high-performance concrete mixture for power plants and a construction method thereof. The interface-hydration synergistic regulation technology is adopted, in which cementitious materials, water, river sand and continuously graded gravel are used as the matrix, and poly-carboxylic acid water reducing agent, crystal nucleus slurry A / B and zwitterionic-hydrophobic copolymer brush modified silica particle B are alternately added in stages to pre-coat and synchronously disperse the coarse aggregate, so that the concrete with long-time slump retention, low bleeding, high early and long-term strength, significantly reduced electric flux and chloride ion permeability, improved sulfate erosion resistance and volume stability is obtained under the conventional mixing and pumping conditions. The in-mold temperature, layered pouring thickness, vibration frequency and curing time limit are specified to ensure the engineering implementability and durability, and the concrete is suitable for power plant structures in high-temperature, high-humidity and chlorine-containing environments, and the construction is reliable and the maintenance is convenient.

The invention discloses a preparation method of an all-solid-waste building material, which comprises the following steps: S1, raw materials of the all-solid-waste building material comprise steel slag, lithium slag, carbide slag and water according to a mass ratio of (11-13): (4-6): 1: (2-4); s2, uniformly mixing and stirring the raw materials in the S1, casting and molding, curing for 2-3 days in an environment with the temperature of 15-25 DEG C and the humidity of 45-55%, and demolding; and S3, after demolding, carrying out carbonization maintenance in an environment with the temperature of 15-25 DEG C and the humidity of 45-55% to obtain the all-solid waste building material. According to the all-solid-waste building material and the preparation method thereof, the steel slag, the lithium slag and the carbide slag are adopted as raw materials, the building material with the strength reaching up to 30 Mpa is prepared, it is guaranteed that the compressive strength is not smaller than 24.3 Mpa, meanwhile, it is guaranteed that the drying shrinkage rate is smaller than 0.29%, the sulfate erosion resistance expansion rate is smaller than 0.07%, and the all-solid-waste building material can replace baking-free bricks to be used in buildings.

This invention proposes a sulfate-resistant silicate cement composite cementitious material based on cement clinker from decommissioned wind turbine blades, its preparation method, and its application. By mass percentage, the raw materials of this cementitious material include 32-40% cement clinker from decommissioned wind turbine blades, 42-50% granulated blast furnace slag powder, 5-9% silica fume, 3-5% gypsum, and 5-8% fly ash. By mass percentage, the mineral composition of the cement clinker from decommissioned wind turbine blades includes 72.0-80.0% C3S, 6.0-14.8% C2S, ≤3.6% C3A, and 9.9-10.7% C4AF, with the total amount of C3S and C2S ≥85%. The technical problem to be solved is how to achieve high-value resource utilization of retired wind turbine blades in a coordinated manner, and to prepare silicate cement composite cementitious materials with both high early strength and excellent resistance to sulfate attack, so that their 3d compressive strength is ≥15MPa, 28-day compressive strength is ≥52MPa, and 28-day corrosion resistance coefficient K is ≥1.1, thus making them more suitable for practical use.

The invention belongs to the technical field of concrete materials, and particularly relates to corrosion-resistant concrete for shield tunnel segments and a preparation method of the corrosion-resistant concrete. The concrete comprises sulphoaluminate cement, fly ash, slag powder, machine-made sand, gravel, a polycarboxylate superplasticizer, a defoaming agent, water and two key modified components, wherein the two key modified components comprise a layered double hydroxide-aluminum silicate nanosheet compound and a phosphate radical intercalation modified strontium molybdate slow-release corrosion inhibitor. During preparation, firstly, all the dry materials are put into a stirrer for dry mixing, then water and the additive are added for stirring to obtain mixed slurry, and a finished product is obtained after pouring, vibrating and steam curing. Wherein the two modified compounds are synthesized through a specific process, the former can adsorb corrosive ions and refine pores, and the latter can slowly release corrosion-inhibiting ions to protect reinforcing steel bars. The prepared concrete has excellent chloride ion penetration resistance, sulfate erosion resistance and carbonization resistance, the durability is remarkably improved, and the concrete is particularly suitable for shield tunnel segments in the severe corrosion environment.

The invention relates to the technical field of concrete, in particular to concrete with high sulfate attack resistance and a preparation method thereof. The invention provides concrete with high sulfate attack resistance, which is prepared from the following components in parts by weight: 250 to 340 parts of Portland cement, 75 to 100 parts of fly ash, 100 to 125 parts of mineral powder, 1250 to 1450 parts of coarse aggregate, 640 to 720 parts of fine aggregate, 50 to 60 parts of epoxy resin, 15 to 25 parts of silica fume, 2 to 3 parts of barium hydroxide, 7 to 12 parts of organic phosphonate grafted polypropylene fiber, 2 to 3 parts of polycarboxylate superplasticizer, 1.5 to 2 parts of defoaming agent and 160 to 180 parts of water. The organic phosphonate grafted polypropylene fiber is obtained by carrying out esterification reaction on diglycolamine dimethylene phosphonate and maleic anhydride grafted polypropylene fiber, wherein the diglycolamine dimethylene phosphonate is prepared by reacting diglycolamine, phosphorous acid and formaldehyde. The concrete prepared by the invention has good sulfate corrosion resistance.

The invention relates to construction and application of a model for predicting the strength and corrosion resistance coefficient of coal gangue concrete under sulfate erosion based on multi-factor fusion, and aims to solve the problems that the deterioration rule of the coal gangue concrete is complicated and the precision of a traditional prediction model is insufficient due to multi-factor nonlinear coupling in a sulfate erosion environment. The method comprises the following steps: (1) constructing a multi-source database containing test data and literature data, wherein the multi-source database contains six types of input characteristics including water-binder ratio, dry-wet cycle age and the like; (2) developing a particle swarm optimization support vector machine (PSO-SVM) model, and quantifying feature importance in combination with an SHAP value analysis method; and (3) establishing a high-precision prediction model, and outputting a compression / breaking strength corrosion resistance coefficient. The method has the remarkable technical effects that the Rvalue of a PSO-SVM model test set reaches 0.912 (compression resistance) and 0.981 (fracture resistance), and the error is smaller than or equal to 20%; it is revealed that the dry-wet cycle age is a key negative influence factor, coal gangue substitution rate optimization design is guided (for example, the fine aggregate substitution rate is controlled to be larger than 20%, and the coarse aggregate substitution rate is controlled to be smaller than 50%), and a reliable tool is provided for concrete durability design in the sulfate erosion environment.

The invention provides an excitation material for a low-concentration high-tail-mud-content all-tailing cementing curing agent and a preparation method of the excitation material, and belongs to the technical field of mining solid waste resource utilization and novel building materials. The excitation material comprises the following components in percentage by weight: 20%-40% of an active silicon-aluminum precursor, 30%-50% of anhydrous gypsum, 10%-20% of quick lime, 5%-15% of modified bentonite, 1%-5% of sepiolite, 5%-10% of heavy calcium carbonate powder and 1%-5% of composite alkali liquor. The excitation material breaks through the solidification bottleneck of the high-mud tailings through double mechanisms of composite excitation and ion slow release, effectively solves the problems of poor cementation solidification effect, difficult construction and the like of low-concentration and high-mud-content full tailings, improves the water stability and sulfate corrosion resistance of a solidified body, and is suitable for being applied to the field of filling of the tailings except for conventional tailing filling application scenes. And the method can be expanded to resource utilization of mud-containing wastes such as river mud and shield muck, and has a wide application prospect.

The present application belongs to a kind of anti-corrosion, anti-crack concrete material for mass concrete engineering;Components and mass fraction are as follows: high iron phase cement 225-378 parts;Fluoroaluminate cement 5-12 parts;Ternary component admixture 158-215 parts;Three-level coarse aggregate 936-1077 parts;Two-level fine aggregate 630-837 parts;The initial slump of prepared concrete material is 180-210mm, 56d compressive strength is 10%-15% more, 7d hydration heat is between 170-210kJ / kg, adiabatic temperature rise is less than 50℃, electric flux is between 600-700C, chloride ion diffusion coefficient is less than 1.8*10 ‑12 m 2 / s, sulphate attack resistance grade is higher than KS90, shrinkage value is less than 300μm / m, which improves the durability and service life of C45-C80 mass concrete structure under high corrosion environment.

The invention discloses a sulfate corrosion resistant method for concrete, and relates to the technical field of civil engineering materials and durability, and the method comprises the following steps: preparing matrix concrete: adopting modified Portland cement with tricalcium aluminate content of 6-8% as a cementing material, and doping a composite mineral admixture accounting for 20-28% of the total mass of the cementing material, the composite mineral admixture is composed of nano metakaolin and superfine slag according to the mass ratio of 1: (1.2-1.5); hydrophobic nano silicon dioxide aerogel particles with the particle size of 50-200 nm and the doping amount of 1.5-2.5 kg / m < 3 > are implanted into the depth interval of 0-15 mm of the concrete surface layer, meanwhile, a shape memory alloy micro wire mesh is embedded and is made of nickel-titanium alloy, the wire diameter is 0.1 mm, and the mesh density is 4 * 4 / cm < 2 >; and in-situ reaction coating generation: alkali-activated geopolymer slurry is sprayed after pouring forming, the modulus of water glass is 1.6-1.8, the solid content is larger than or equal to 65%, and an inorganic-organic hybrid protective layer matched with the thermal expansion coefficient of a concrete matrix is formed through curing.

This application relates to the field of magnesite concrete, and specifically discloses a magnesite concrete with high sulfate erosion resistance and a preparation method thereof. The magnesite concrete comprises the following components in parts by weight: 360 - 430 parts of cement, 1128.5 - 1146.6 parts of coarse aggregate, 663 - 689 parts of fine aggregate, 11.52 - 13.76 parts of silica fume, 160 - 185 parts of mixing water, 3.2 - 3.8 parts of water reducer, 17.28 - 20.64 parts of gneiss powder, and 6.12 - 7.36 parts of sulfate corrosion inhibitor; the preparation method is: first, mix and stir all raw materials except mixing water and water reducer, and then add mixing water and water reducer and continue to stir to obtain the magnesite concrete with high sulfate erosion resistance. The magnesite concrete of this application has strong mechanical properties and sulfate erosion resistance, and excellent durability.

This invention provides a method for quantitatively assessing the degree of sulfate attack on concrete, relating to concrete attack assessment technology, including: plotting SO4... 2‑ Concentration standard curve; determination of free SO4 in the sample. 2‑ Content, denoted as C （游离） Determine the total SO4 content of the same mass of test samples from the same source. 2‑ Content, denoted as C （总） C （总） With C （游离） The difference is the content of bound sulfate ions in the sample to be tested, denoted as C. （AFt，AFm） ; Calculate the bound sulfate content C per gram of the sample to be tested. 1 （AFt，AFm） :;C 1 （AFt，AFm） The value represents the amount of ettringite and monosulfide-type hydrated calcium sulfoaluminate formed. Using the formation of ettringite and monosulfide-type hydrated calcium sulfoaluminate as an evaluation index, the degree of sulfate attack on concrete is assessed. This method achieves a quantitative assessment of the degree of sulfate attack on concrete from the perspective of the chemical nature of the attack, and features accurate quantification, simple operation, and the ability to distinguish SO4. 2‑ Advantages such as shape.

The invention provides a concrete compressive strength prediction method based on the combined action of fatigue load and sulfate, which comprises the following steps: firstly, dividing concrete into a degraded area, an enhanced area and an intact area, establishing a compressive strength prediction model only considering sulfate erosion, and then, describing the time-varying diffusion depth of sulfate ions by introducing a power function, so as to predict the compressive strength of the concrete. And correcting key parameters of the diffusion model by using fatigue damage parameters, and finally, coupling to construct a compressive strength model capable of accurately reflecting the combined action of fatigue load and sulfate. According to the method, the technical problem that an existing model cannot accurately describe non-uniformity of an erosion space and a multi-factor coupling effect is effectively solved, a model prediction value is well matched with an experimental value, and a reliable basis is provided for durability design and service life prediction of a concrete structure in a complex environment.

The invention discloses a preparation method of anti-corrosion concrete for a saline soil area based on lithium slag, and belongs to the technical field of building materials. According to the method, the lithium slag is used as an admixture to be applied to concrete preparation, and the impermeability, chloride ion permeability resistance and sulfate erosion resistance of the concrete are improved by utilizing active ingredients and a micro-aggregate effect of the lithium slag, so that the corrosion resistance of the concrete in a saline soil region is remarkably enhanced. According to the invention, the resource utilization of the industrial solid waste lithium slag is realized, the production cost of the concrete is reduced, the service life of the concrete structure in the saline soil region can be effectively prolonged, and the method has remarkable economic benefits and environmental benefits.

The invention discloses a multistage slow-release targeted control agent aiming at sulfate erosion expansion of a cement-based material as well as a preparation method and application of the multistage slow-release targeted control agent. The multistage slow-release targeted control agent comprises an active aluminum-based inner core, a PVA-boric acid hydrogel (PBH) inner shell layer coating the surface of the inner core, and a hydrogel outer shell layer (PPH) which coats the inner shell layer and can be dissociated in an alkaline environment. The multi-stage slow-release targeted control agent can promote accurate growth of the expansive hydration product in preset micropores of a cement-based material, the strength of the generated expansive hydration product is high, and the problem of stress concentration damage caused by defects caused by insufficient strength at pores is avoided.

This invention discloses a method for sulfate erosion protection and repair of slope drainage facilities, comprising: setting up retaining walls at both ends of the drainage ditch on the slope to be repaired; removing debris from the drainage ditch; chiseling away the concrete structure at the eroded part; and repairing the base layer of the drainage ditch; laying grouting pipes along the drainage ditch and injecting grouting material into the contact surface between the bottom of the slope drainage facility and the soil through the grouting pipes; the grouting material hardens to form an impermeable isolation layer; spraying polymer-modified sulfoaluminate cement emulsion onto the surface of the base concrete structure according to the sulfate concentration obtained by testing, or first applying a base treatment agent and then hot-melt laying a waterproof membrane, or hot-melt laying and fixing the waterproof membrane and covering the entire surface; removing the retaining walls to complete the repair. Through the technical solution of this invention, existing defects are eliminated, the resistance to sulfate erosion is enhanced, and the stability and durability of concrete equipment under special geological conditions are greatly improved.

Lime-based cement extender or cement replacement compositions and formulations, and associated systems and methods are disclosed herein. In some embodiments, a lime-based cement extender or cement replacement composition includes at least 5% by weight lime particles and at least 50% by weight pozzolan particles. In some embodiments, the pozzolan particles include silicon dioxide and aluminum oxide. In some embodiments, composition can be combined with admixtures and / or aggregates to produce a formulation. The formation can have at least 5,000 ppm soluble sulfate and an alumina:silica ratio of at least 0.2:1. Methods of accelerating formation of calcium aluminum sulfates to avoid sulfate attacks during critical periods include producing a formulation with high aluminum oxide content, admixtures configured to accelerate certain chemical reactions, and omitting limestone. Methods of delaying formation of calcium aluminum sulfates to avoid sulfate attacks during critical periods include producing a formulation with admixtures configured to delay certain chemical reactions.

The invention belongs to the technical field of concrete, and particularly relates to limestone powder self-compacting concrete and a preparation method thereof. The invention provides limestone powder self-compacting concrete. Each cubic meter of the limestone powder self-compacting concrete is prepared from 360 to 427 kg of cement, 23 to 90 kg of limestone powder, 1750 to 1830 kg of aggregate, 145 to 160 kg of water and 4 to 4.5 kg of additive, the mass of the limestone powder is 5-20% of the total mass of the cement and the limestone powder, and the additives comprise a polycarboxylic acid water reducing agent, a defoaming agent, a retarder, a chelating agent and an air entraining agent. The self-compacting concrete provided by the invention has relatively high workability, is easy to construct, and can reduce voids and pitted surfaces in a pouring process, so that the compactness and strength of the concrete are improved. Meanwhile, the self-compacting concrete provided by the invention has excellent sulfate attack resistance, the use scene of the self-compacting concrete can be further expanded, and the durability of the self-compacting concrete is improved.

The invention relates to the technical field of building materials, in particular to a geopolymer with a self-enhancement function, a preparation method and application. The geopolymer is prepared by the preparation method. The preparation method comprises the following steps: feeding and uniformly mixing metakaolin and slag according to a mass ratio of 4: 6 to obtain a precursor; uniformly mixing an alkali activator, water and the precursor according to a mass ratio of 4: 35: 100 to obtain a reaction system; and injecting the reaction system into a mold, carrying out first maintenance, demolding, and then carrying out second maintenance to obtain the geopolymer with the self-enhancement function. The application comprises application of the geopolymer in a dry-wet alternating environment and application of the geopolymer in a chemical medium erosion environment. According to the invention, the geopolymer which has high initial strength and shows a reactive self-enhancement function in harsh environments such as dry-wet alternation, chemical medium (such as sulfate) erosion and the like can be prepared at low cost, so that the durability of the geopolymer is improved.

The present application relates to a kind of anti-sulphate erosion preservatives and its preparation method, a kind of anti-sulphate erosion preservatives, preparation raw materials of the anti-sulphate erosion preservatives include: dense component 25-55 parts;Expanding agent 15-40 parts;Ion curing agent 5-10 parts;Preservative adjuvant 10-20 parts;And inhibitor 3-10 parts.The anti-sulphate erosion preservatives prepared in the present application has super strong anti-sulphate erosion performance, after adding the anti-erosion agent in concrete, dense structure can be formed in the interior of concrete, reduce concrete cracking.The present application is lower than traditional method using anti-sulphate cement single concrete cost, anti-sulphate erosion capacity and anti-chloride ion penetration capacity are significantly improved, with higher economic and social benefits.