378 results about "Cement particle" patented technology

The invention provides a cement particle grading optimization method and system for minimizing porosity, and relates to the technical field of cement material science and engineering, and the method comprises the following steps: obtaining cement particles with different particle size distributions; taking the cement particles as spheres, and generating a sphere set according to the cement particles with different particle size distribution; in the sphere set of each particle size distribution, sampling according to a proportion, and constructing a three-dimensional simulation microstructure model by using the sampled spheres; simulating a sphere accumulation process in a three-dimensional box by using a three-dimensional simulation microstructure model, calculating the porosity in the three-dimensional box in the simulation process, establishing a loss function according to the overlapping volume between spheres and the collision volume between the spheres and the boundary, and obtaining the porosity of cement proportions with different particle size distributions by using a gradient descent method; and adjusting the sampling proportion of each particle size distribution by adopting an optimization algorithm so as to minimize a loss function and realize the grain composition of the cement powder with the minimum porosity and different distribution so as to optimize the strength of the cement.

The invention discloses a nano material modified alcohol amine grinding aid as well as a preparation method and application thereof, and the preparation method comprises the following steps: firstly, carrying out esterification reaction on alcohol amine and an acid small monomer containing double bonds to generate an esterification product; then, carrying out bulk polymerization on the esterification product and a silane coupling agent KH-570; and finally, combining the bulk polymerization product with the nano-material through a dehydration reaction of a silane coupling agent and hydroxyl on the surface of the nano-material to form the nano-material modified alcohol amine grinding aid. According to the invention, the nano material is directly grafted into the alcohol amine, so that the dispersity of the nano material in the cement grinding process can be effectively optimized, the friction force and energy consumption among cement particles can be reduced, the efficiency and stability of the cement production process can be improved, and the strength and durability of the cement product are improved.

The invention relates to the technical field of concrete, and particularly discloses super-retarded concrete for an ultra-large pile and a preparation method of the super-retarded concrete. The super-retarding concrete for the ultra-large pile is prepared from the following raw materials in parts by mass: 320 to 400 parts of a cementing material, 1820 to 1960 parts of aggregate, 20 to 28 parts of an inorganic-organic hybrid retarding reinforcing agent, 7.2 to 11.6 parts of a polycarboxylate superplasticizer and 85 to 98 parts of water, the inorganic-organic hybrid delayed coagulation enhancer is prepared by carrying out in-situ free radical polymerization reaction on a hydroxyl acrylate monomer, acrylamide and nano silicon dioxide. According to the inorganic-organic hybrid retarding reinforcing agent, a hybrid substance is formed through a chemical bond, an organic phase is chelated with calcium ions to realize retarding and does not excessively inhibit cement particles, inorganic phase nano silicon dioxide has no agglomeration risk, gaps are filled, a stable product is generated to resist alkali erosion, and the super retarding performance and the long-term strength of concrete are both considered; and the service life of the ultra-large pile is prolonged.

The invention discloses a cement-based material mixing state intelligent regulation and control auxiliary agent and a preparation method and application thereof. The auxiliary agent is composed of reversible sulfonation modified degradable starch and acrylic resin containing hydroxyl. The method is characterized in that the sulfonated modified starch plays roles in dispersing and suspending cement particles and gravels and improving uniformity and flowability in the cement-based material mixing and injection molding stages, and the sulfonated starch is stimulated to be reversibly reduced into dialdehyde starch in a cement paste alkaline environment in the curing and curing stage; the molecules are mutually crosslinked to form a three-dimensional network structure, so that the effects of dispersing, suspending, adhering and fixing cement particles and gravels are achieved. Therefore, the prepared cement-based material mixing state intelligent regulation and control auxiliary agent has the intelligent effects of presenting different molecular structures and playing different roles in the stirring, injection molding and curing states, the preparation method is unique, the materials are easy to obtain, the application effect is remarkable, and the good application prospect is achieved.

The invention relates to an admixture for a cementitious material suitable to influence the rheological properties of the cementitious material. The admixture includes a compound having a backbone chain provided with at least one first functionality and at least one second functionality. The at least one first functionality is adapted to adsorb to the cement particles of the cementitious material. The at least one second functionality is adapted to respond to an external trigger signal of an electric field, a magnetic field or an electromagnetic field, thereby influencing the rheological properties of the cementitious material. The rheological properties are influenced by influencing the interaction of the at least one first functionality with the cement particles and / or by influencing the interparticle interaction between the cement particles. The invention further relates to a cementitious material including such admixture. Furthermore, the invention relates to a method and a system to control or influence the rheological properties of a cementitious material.

The invention discloses a super-retarding type polycarboxylic acid water reducing agent and a preparation method and application thereof, and belongs to the field of concrete water reducing agents. The preparation method comprises the following steps: taking acrylic acid AA, isobutenol polyoxyethylene ether HPEG and hydroxyethyl acrylate HEA as monomers, taking mercaptopropionic acid MPA as a chain transfer agent, taking hydrogen peroxide H2O2 and L-ascorbic acid Vc, and mixing in proportion to serve as an initiator; preparing a first and second monomer mixed solution; adding bottom water into the reaction kettle, and carrying out stepwise polymerization reaction; and cooling the reaction liquid, adjusting the pH value, filtering, and discharging to obtain the product. According to the invention, an ester functional monomer hydroxyethyl acrylate HEA is introduced, and a step-by-step polymerization technology is adopted to control the dispersion process of water reducing agent molecules on cement particles, so that the water reducing agent molecules continuously disperse the cement particles within a certain period of time; the problem that the slump loss is too fast due to long-time and long-distance transportation of concrete or transportation in high-temperature weather is effectively relieved.

The invention belongs to the technical field of preparation of water reducing agents, and particularly relates to a slump-loss-free super-slow-release type water reducing agent mother solution and a preparation process thereof. The method comprises the following steps: copolymerizing a phosphoric acid functional monomer, an amide functional monomer, a polyether monomer and unsaturated carboxylic acid to obtain a mother solution of the super-slow-release water reducing agent; functional groups such as acylamino and ester groups introduced on a molecular chain of the water reducer can be slowly hydrolyzed into anion anchoring groups such as carboxyl in an alkaline environment, so that secondary adsorption of the water reducer and cement particles is promoted, and the water reducer has relatively long slump retaining performance and relatively high compressive strength.

The invention relates to the technical field of cement-based materials, in particular to a preparation method of a special ultra-high-strength cement-based grouting material for wind power generation, which comprises the following steps of: performing simulation analysis on stress and bonding conditions in a contact area of cement particles and aggregate particles by quantifying the proportion of cement, aggregate and an additive and adopting a discrete element method; gap distribution among particles is adjusted in combination with a genetic algorithm, mechanical behaviors of the particles are refined through application of a discrete element method, the problem of local stress concentration possibly caused by particle arrangement randomness is avoided, microcosmic stress distribution data are continuously mapped through a radial basis function interpolation method, and the stability of the microcosmic stress distribution data is improved. A macroscopic stress distribution model is established by adopting finite element analysis, data support is provided for the crack resistance and bearing capacity design of the material, the comprehensive performance of the cement-based grouting material in the aspects of fatigue resistance, deformation resistance, environmental erosion resistance and the like is improved by optimizing the synergistic effect of a microstructure and macroscopic stress, and the comprehensive performance of the cement-based grouting material in the aspects of fatigue resistance, deformation resistance, environmental erosion resistance and the like is improved. The mechanical stability and the long-term durability are ensured.

The invention relates to the technical field of concrete admixtures in building materials, in particular to a viscosity reduction type polycarboxylic acid water reducer suitable for high-strength concrete and a preparation method of the viscosity reduction type polycarboxylic acid water reducer. The hydrophobic modified unsaturated double-chain polyether macromonomer is prepared from the following components in parts by mass: 20 to 30 parts of unsaturated acid, 200 to 300 parts of hydrophobic modified unsaturated double-chain polyether macromonomer, 10 to 15 parts of phosphate monomer, 2 to 4 parts of oxidizing agent, 1 to 2 parts of reducing agent, 1 to 2 parts of chain transfer agent, 5 to 10 parts of neutralizing agent and 120 to 180 parts of water. According to the invention, the polyether chain can unfold in a pore solution, the steric hindrance effect is further enhanced, cement particles are ensured to be effectively dispersed in a compact space, and meanwhile, the hydrophobic part of the side chain can effectively reduce the surface tension of the pore solution, so that the condition of overhigh viscosity is avoided, and the flowability and constructability of the concrete are improved.

The invention relates to the technical field of polycarboxylate superplasticizers, and discloses a durability-enhanced polycarboxylate superplasticizer and a preparation method thereof.The preparation method comprises the following steps that raw materials such as a polyether macromonomer are prepared, the polyether macromonomer and the like have the requirements for purity and dosage, deionized water and the polyether macromonomer are added into a reaction kettle to form a solution A, and the solution A is prepared; and preparing an initiator solution B with the mass concentration of 10-20% from ammonium persulfate, heating to 60-80 DEG C, stirring, firstly adding 1 / 3 of the initiator solution B to react, then preparing a mixed monomer solution from acrylic acid and the like, dropwise adding the mixed monomer solution and the residual initiator solution B within 2-3 hours, carrying out heat preservation reaction, cooling, and regulating the pH value to 6-8 by using sodium hydroxide to obtain a finished product. The sulfonic acid group of the introduced sodium methallyl sulfonate functional monomer can enhance the electrostatic repulsion between water reducer molecules and cement particles, so that the dispersing performance of the water reducer is improved, the agglomeration of the cement particles can be inhibited to a certain extent, and the fluidity of concrete can be maintained.

The invention discloses a retarder for delaying cement setting time and a preparation method thereof, and belongs to the field of cement admixtures. The retarder is anionic polymer modified chitosan, and the preparation method comprises the following steps: (1) fully dissolving chitosan in a weak acid solution to obtain a chitosan solution; (2) fully dissolving an anionic polymer in a solvent to obtain an anionic polymer solution; and (3) adding the anionic polymer solution into the chitosan solution, fully stirring, carrying out electrostatic adsorption reaction, and centrifuging, washing, drying and crushing after the electrostatic adsorption reaction is finished to obtain the anionic polymer modified chitosan. Chitosan is modified through electrostatic adsorption of an anionic polymer to form a compound, the compound is added into cement, and the coagulation time of the cement is prolonged by utilizing the complexing action of functional groups of the compound on calcium ions and the surface adsorption action on cement particles, so that the construction operability is favorably improved; and the preparation process is simple, and the cost is low.

The invention provides a viscosity reduction type concrete super plasticizer and a preparation method and application thereof.The super plasticizer is solid and is prepared from an unsaturated monomer a, an unsaturated monomer b and an unsaturated monomer c through free radical polymerization under the microwave condition, the unsaturated monomer a is methacrylic acid or methyl alkenyl phosphonic acid monomer, and the unsaturated monomer b is methacrylic acid or methyl alkenyl phosphonic acid monomer. The unsaturated monomer b is a monomer containing a rigid ring, the rigid ring is an aromatic ring or an imidazole ring or a pyridine ring, and the unsaturated monomer c is an unsaturated polyether monomer containing a benzene ring. A methyl group and a rigid ring group are introduced into a main chain of the super plasticizer, so that the rigidity of a polymer is improved, the hydrophobicity is increased, the conformation of the polymer is changed, and a relatively thick water film layer is formed on the surface of cement particles; meanwhile, a branched structure side chain is introduced into the super plasticizer, so that the molecular size of the polymer can be remarkably increased, the steric hindrance effect of the polymer is more outstanding, the dispersing capacity is good, the thickness of a water film layer on the surface of cement can be increased, and the viscosity of concrete is further reduced.

The invention discloses low-hydration-heat iron aluminate cement and a preparation method thereof, and belongs to the technical field of maritime work cement, and the low-hydration-heat iron aluminate cement comprises 70-85 parts of iron aluminate cement clinker, 5-7 parts of a bio-based retarder, 4-8 parts of a nano friction regulator, 3-4.5 parts of a microcapsule dual repair agent, 5-10 parts of gypsum and 15-25 parts of a mixed material. The fucoidan polysaccharide sulfate and calcium ions in a cement hydration product form a complex through sulfate groups in molecules of the fucoidan polysaccharide sulfate, and further hydration of cement particles is prevented, so that the early heat release rate is effectively reduced, temperature cracks are prevented from being generated in a concrete structure, and the stability and durability of the structure are improved. According to the microcapsule dual-repairing agent, the problem of delayed volume expansion of the steel slag powder caused by fluctuation of the content of free calcium oxide is effectively solved through the matching effect of the inner-layer repairing agent and the outer-layer carrier. According to the gradient clinker sintering process, mineral distribution and chemical reaction paths in clinker are optimized, so that the generation amount of cement hydration heat is remarkably reduced, and meanwhile, the thermal stability of slurry is improved.

The present invention relates to the technical field of concrete admixtures, and particularly relates to a hydroxyl-terminated polyether macromonomer and a preparation method therefor, and a low-temperature rapid-dispersion-type ether polycarboxylic acid superplasticizer and a preparation method therefor. The ether polycarboxylic acid superplasticizer is formed by copolymerizing the hydroxyl-terminated polyether macromonomer, acrylic acid and a functional monomer C by means of a copolymerization reaction. The ether polycarboxylic acid superplasticizer, which is prepared by using the specific hydroxyl-terminated polyether macromonomer in the present invention, has a significantly improved adsorption rate and early-stage adsorption capacity on the surfaces of cement particles; in addition, the adsorption capacity of the superplasticizer in the later stage can be kept at a relatively high level, the cement paste dispersion time of cement using the superplasticizer is short, and the requirements of the superplasticizer are less while satisfying the same initial cement paste fluidity requirement; and the superplasticizer has a high dispersion speed, good dispersion performance, and good slump-retaining performance at low temperatures.

The invention relates to the technical field of intelligent grouting, in particular to an intelligent grouting method based on real-time permeability monitoring, which comprises the following steps: arranging a pressure monitoring array in a to-be-grouted area, and electrically connecting the pressure monitoring array with a controller; grouting is started, and the time when the grout reaches all the measuring points is obtained; the stratum permeability change condition is calculated; and dynamically adjusting grouting parameters according to the permeability change condition, wherein the grouting parameters comprise grouting pressure, a water-cement ratio and a cement particle size. According to the method, the grouting target is achieved most efficiently, most economically and most safely through the most appropriate grout, and the problems that in a traditional grouting technology, grouting is not uniform, the reinforcing effect is poor, and potential safety hazards are large are solved. And the grouting parameters are dynamically adjusted based on the change of the permeability, it is ensured that proper grout is injected, the construction quality and efficiency are improved, and intelligent development of the grouting technology is further promoted.

The invention relates to low-cost retarded concrete and a preparation method thereof. The low-cost retarded concrete comprises the following components in parts by weight: 24-27 parts of cement, 6-8 parts of blast furnace slag powder, 5-8 parts of fly ash, 70-90 parts of fine aggregate, 2-7 parts of sludge incineration ash, 93-100 parts of coarse aggregate, 0.4-0.6 part of a water reducing agent, 0-0.25 part of a retarder and 12-21 parts of water. When the temperature of the production environment is lower than 30 DEG C, the retarder comprises sodium gluconate; when the temperature of the production environment is higher than or equal to 30 DEG C, the retarder further comprises white sugar. According to the invention, the sludge incineration ash is recycled, phosphate radicals dissolved in the sludge incineration ash are combined with calcium ions generated by cement hydration, and the calcium ions coat the surfaces of cement particles to hinder further hydration of cement, so that the purpose of retarding is achieved, and the cement can be retarded by increasing the mixing amount of the sludge incineration ash and the retarder. The retarded concrete meeting different setting time requirements can be prepared; other components in the sludge incineration ash can be subjected to secondary hydration reaction with calcium hydroxide generated by cement hydration, so that the durability of the concrete can be improved.

The invention provides a viscosity reduction type water reducer as well as a preparation method and application thereof. The water reducer is prepared by the following steps: firstly, alternately polymerizing styrene and maleic anhydride to obtain a low-molecular-weight styrene-maleic anhydride polymer, and then respectively grafting a phosphonic acid monomer and a polyether monomer into a main chain of the styrene-maleic anhydride polymer through reaction, the number average molecular weight of the styrene-maleic anhydride polymer is 1000 to 2000. Through an esterification reaction, a phosphonic acid monomer and a polyether monomer are grafted to a main chain formed by a styrene-maleic anhydride alternating polymer, and a phosphonic acid group and a hydrophobic epoxypropane structural unit are introduced into a water reducing agent structure, so that the surface tension of the water reducing agent is further reduced; the wetting effect and a certain air entraining effect of the water reducing agent on cement particles are improved, the sliding resistance among the cement particles is reduced, and the viscosity of concrete is reduced to a certain extent.

The invention relates to a concrete slump retaining agent and a preparation method thereof, and the concrete slump retaining agent is prepared from the following raw materials in parts by weight: 2.13-4.25 parts of unsaturated phosphate functional monomer; 200 to 220 parts of polyether monomer; 10 to 20 parts of unsaturated acid; 20 to 30 parts of acrylic ester; 0.53 to 0.97 part of a chain transfer agent; 0.91 to 2.06 parts of an oxidizing agent; 0.20 to 0.75 part of a reducing agent; and 245 to 265 parts of water. Wherein the unsaturated phosphate functional monomer is prepared from the following raw materials: polyethylene glycol, unsaturated organic phosphoric acid and a catalyst. The unsaturated phosphate functional monomer is introduced into the concrete slump retaining agent, and when the concrete slump retaining agent is applied to concrete, unsaturated phosphate in the unsaturated phosphate functional monomer can form a stable complex with calcium ions on the surfaces of cement particles, so that active sites, capable of being adsorbed by mud particles, on the surfaces of the cement particles can be reduced; the concrete can keep good flowability within a certain time, so that the slump retaining and mud resisting effects are achieved.

The present invention relates to the technical field of concrete admixtures, and particularly relates to a rapid-dispersing polycarboxylate water reducer and a preparation method thereof. The water reducer is copolymerized from an acetyl-capped polyether macromonomer, acrylic acid, an ester macromonomer and functional monomer C through a copolymerization reaction. The rapid-dispersing polycarboxylate water reducer prepared by using a specific acetyl-capped polyether macromonomer in the present invention has a significantly improved adsorption rate and early adsorption amount on the surface of cement particles, and the later adsorption amount of the water reducer can be maintained at a relatively high level. The net paste dispersion time of the cement using this water reducer is short, and less of this water reducer is required to meet the same initial net paste fluidity requirement. This water reducer has a fast dispersion speed, good dispersion performance and good slump retention performance at low temperatures.

The invention discloses a frost-crack-resistant salinized soil curing agent based on a nano material and a preparation method thereof, and relates to the technical field of soil curing agents. The preparation method of the curing agent comprises the following steps: uniformly stirring and mixing the cement and the basalt fiber to obtain a premix; adding silica fume, nano silicon dioxide and polyacrylamide into the premix, and continuously stirring and uniformly mixing to obtain the frost crack resistant saline soil curing agent based on the nano material. The silica fume and the nano silicon dioxide are used, so that gaps among cement particles can be effectively filled, the porosity is reduced, and the compactness of the solidified soil is improved; after the nano silicon dioxide is hydrophobically modified by the polydimethylsiloxane, a hydrophobic network is formed in the material, and water permeation is further hindered. And meanwhile, due to the reinforcement function of the basalt fibers and the spatial reticular reinforcement structure constructed by polyacrylamide, the cracking resistance of the soil body is enhanced.

The invention belongs to the technical field of cement grinding aids, and particularly relates to an efficient cement grinding aid and a preparation method thereof.The efficient cement grinding aid is prepared from, by weight, 15%-30% of polyhydric alcohol compounds, 10%-15% of organic acid salt, 12%-20% of a surfactant, 10%-15% of a reinforcing agent and 0.3%-5% of a defoaming agent; the invention further discloses a preparation method of the efficient cement grinding aid. The preparation method comprises the following preparation steps: S1, raw material pretreatment; s2, mixing and dispersing; s3, preparing solid raw material spherical particles; s4, dissolving; s5, adding nano silicon dioxide and modified starch; and S6, post-processing. The cement grinding aid disclosed by the invention can be used for refining cement particles and optimizing particle composition, so that the specific surface area of cement is increased, the problems of caking of raw materials and non-uniform local concentration are effectively avoided, and the mixing effect is improved.

The invention discloses a chemically refined high-strength cement grouting material as well as a preparation method and application thereof, and belongs to the technical field of geotechnical engineering. The chemically refined high-strength cement grouting material is prepared from the following raw materials in parts by weight: 300 to 500 parts of cement, 50 to 150 parts of fly ash, 2.5 to 5 parts of nano silicon dioxide, 5 to 10 parts of a water reducing agent, 0 to 10 parts of an activating agent and 200 to 400 parts of water, wherein the weight part of the activating agent is not 0. According to the invention, the activator is used for accelerating the dissolution, decomposition and hydration of cement particles, and the early strength of the finally prepared grouting material is greatly improved in cooperation with nano-modification and dissolution-nucleation; the preparation method is simple and easy to implement and low in energy consumption, the production cost is reduced, and industrial production of the grouting material is promoted.

The invention provides a high-temperature-resistant oil well cement retarder and a preparation method thereof, and relates to the technical field of cement retarder materials. The high-temperature-resistant oil well cement retarder is prepared from the following materials in parts by weight: 30 to 40 parts of sulfo-siloxane grafted lignosulfonate, 5 to 10 parts of self-repairing microcapsules, 5 to 8 parts of zinc oxide, 2 to 3 parts of hexagonal boron nitride nanosheets, 1 to 2 parts of pH buffering agent, 2 to 4 parts of polycarboxylic acid water reducing agent and 8 to 12 parts of deionized water. According to the high-temperature-resistant oil well cement retarder disclosed by the invention, the temperature resistance of the high-temperature-resistant oil well cement retarder is improved; the phenomena of bulging, core wrapping and the like in a high-temperature experiment are avoided; the dispersion uniformity of the high-temperature-resistant oil well cement retarder on cement particles is improved, and local premature solidification or excessive retarding in cement paste is prevented; the problem that the strength is reduced due to the fact that retarder components are adsorbed on the surfaces of cement particles to hinder formation and growth of hydration products is solved.

The present application relates to the field of concrete technology, and in particular to a non-structural steel slag anti-floating weighted concrete that can replace all aggregates. The anti-floating weighted concrete comprises cement, fine aggregate steel slag, coarse aggregate steel slag and a modifier. The modifier includes a polymer polymerized by methacrylic acid, 4,4'-diaminobenzyl-2,2'-disulfonic acid and n-butyl isobutyrate. The fine aggregate steel slag and coarse aggregate steel slag completely replace conventional sand and gravel fine aggregate and coarse aggregate, which can not only reduce the occupation of land and environmental pollution by industrial waste steel slag, but also reduce the material cost of concrete. The modifier has a highly polar hydrophilic group, which is doped in cement, can efficiently bind to the water molecules inside the concrete, attach to the cement particles bound to the water molecules, disperse the cement particles, improve the workability of the fresh concrete, improve the density of the concrete after solidification, and improve the impermeability, compressive strength, crack resistance and impact resistance of the concrete after solidification.

The invention discloses an additive for inhibiting mud powder in machine-made sand and a preparation method of the additive, and belongs to the technical field of building materials.The additive is prepared from a mud blocking component A, a sacrifice component B and a retarding component C. The mud blocking component A plays a role in neutralizing negative charges on the surfaces of mud powder particles and can separate water from clay, and the sacrifice component B plays a role in retarding the mud powder particles; water adsorbed by the layered structure of the clay is reduced, so that free water in the cement paste is increased, and the water demand of the concrete and the adsorption of the clay powder to an additive are reduced. The molecular structure of the sacrifice component B has the characteristics of short side chain, high acid-ether ratio, high charge density and small molecule, and can be adsorbed and inserted in a layered structure of mud powder more quickly than a conventional polycarboxylic acid water reducing agent, so that the adsorption of the mud powder on the water reducing agent is reduced. The retarding component C can form a complex with calcium ions in a solution, so that precipitation of calcium hydroxide is inhibited, hydration of cement is delayed, plasticity retaining property of concrete is improved, cement particle distribution can be improved, and concrete shrinkage caused by mud powder is reduced.

The invention discloses an air-entraining type viscosity-reducing polycarboxylic acid water reducer and a preparation method thereof, the polycarboxylic acid water reducer is prepared by taking unsaturated polyether macromonomer, unsaturated acid monomer, vinyl polyacetylene monomer and functional monomer as main raw materials through free radical polymerization reaction under the action of an oxidizing agent, a reducing agent and a chain transfer agent. The unsaturated acid monomer is introduced, so that water reducer molecules can be well adsorbed on the surfaces of particles, the electrostatic repulsion effect is exerted, and the particles are further dispersed; the vinyl polyacetylene monomer and the functional monomer are subjected to gradient hydrolysis in alkaline cement paste, carboxyl is gradually released, and the re-adsorption-dispersion effect of water reducing agent molecules on cement particles within a long time is ensured, so that the slump loss is effectively reduced, and the concrete workability is improved. And the process is simple, the raw materials are cheap, large-batch production and manufacturing are facilitated, and the batch concrete matching and selecting requirements are met.

The invention relates to the technical field of cement additives, in particular to a powder composition for cement addition and a preparation process of the powder composition, modified sodium lignin sulfonate serves as an important component of the powder composition, dispersity and stability of sodium lignin sulfonate are effectively improved through sulfomethylation and condensation reaction, and in cement concrete, the powder composition has the advantages that the dispersity and stability of sodium lignin sulfonate are improved; the modified sodium lignin sulfonate can be adsorbed on the surfaces of cement particles to form a protective film, friction force and resistance among the cement particles can be reduced, so that the fluidity of the concrete is improved, meanwhile, a sulfomethylation structure of the modified sodium lignin sulfonate can chemically react with calcium ions in the cement to form stable calcium salt, the stability of the concrete is further enhanced, and the service life of the concrete is prolonged. According to the powder composition for cement addition and the preparation method of the powder composition, the performance of cement concrete can be remarkably improved through well-designed components, and the composition has excellent flowability, anti-permeability, anti-freezing property, water resistance, mildew resistance and rust resistance.

The invention relates to the technical field of cement grinding aids, in particular to a composite liquid cement grinding aid and a preparation method of the composite liquid cement grinding aid. Maleic anhydride, triethanolamine, acrylic acid and isopentenyl polyoxyethylene ether are used as raw materials in a macromolecular grinding aid solution; a reaction product of maleic anhydride and triethanolamine can form a compound with special functional groups, the functional groups can be effectively adsorbed on the surfaces of cement particles, friction among the particles is reduced, the grinding efficiency is improved, and the dispersity and stability of the grinding aid can be further enhanced by adding acrylic acid and isopentenyl polyoxyethylene ether, so that the grinding aid has a good application prospect. The cement particles are more easily dispersed in water, the agglomeration phenomenon is reduced, and the refining of the cement particles is facilitated; according to the invention, sodium lignin sulfonate is modified by grafting diethanolamine, and on the basis of retaining the original dispersibility of sodium lignin sulfonate, a new functional group is introduced, so that the interaction between sodium lignin sulfonate and cement particles can be enhanced, and the grinding aiding effect is further improved.

The invention relates to the technical field of building materials, and discloses an alumino-ferroate cement water reducer and a preparation method thereof. The prepared unsaturated zwitterionic cyclodextrin is polymerized with maleic anhydride and acrylic acid to obtain the alumino-ferroate cement water reducer. The cyclodextrin has a hollow cylindrical stereoscopic structure, which brings a significant steric hindrance effect to the polymer. The sulfonic acid groups on the main chain of the water reducer are anchored on positively charged cement particles to generate strong adsorption. The quaternary ammonium salt cations can be adsorbed on the surface of the negatively charged cement particles, so that the cement particles can achieve a better dispersion effect and the fluidity of the cement paste is improved. The presence of the cyclodextrin side chain and the polyethylene glycol long chain affects the cement hydration process, can effectively weaken the interpenetration between the water reducer molecules and the clay layer, enriches the preparation method of the synthetic alumino-ferroate cement water reducer, and is easy to realize industrial production.

The invention provides a concrete workability improved water reducing agent with a polyphosphate side chain as well as a preparation method and application of the water reducing agent. The water reducing agent is prepared from a phosphate macromonomer and a charged monomer through free radical copolymerization, the structure is characterized in that a side chain contains a large number of P-O bonds and has high ductility, and a main chain adsorption group has a flexible chain segment formed by ester bonds. The side chain segment of the water reducing agent contains a large number of P-O bonds, the hydrogen-bond interaction is stronger than that of the conventional polyether polyol chain segment, the ductility of the side chain in a slurry solution is increased, the thickness of an adsorption layer of the water reducing agent on the surface of cement particles is increased, and the water reducing agent has high dispersity; an electrified monomer with a flexible chain segment is used as an adsorption unit of water reducing agent molecules, the effect of adsorption base embedding caused by curling and folding of a polymer chain segment is avoided, the electrostatic adsorption effect of the water reducing agent molecules on the surfaces of cement particles is effectively enhanced, the cement adaptability is improved, and the sensitivity is reduced.