67results about How to "Improve early strength performance" patented technology

The invention relates to a high-performance anti-cracking anticorrosive water reducing agent composition and a preparation method thereof. The anti-cracking anticorrosive waterproof anti-frost property of the water reducing agent composition is improved while the water-reducing rate of the water reducing agent composition is increased. Compared with a water reducing agent in the prior art, the water reducing agent composition has excellent combination property and an anti-cracking anticorrosion effect. When the water reducing agent composition is prepared, low energy is consumed, and when the water reducing agent composition is used, little pollution is caused.

The invention discloses a compound concrete admixture with early strength and water reduction functions. The compound concrete admixture is mainly prepared by 10-20 parts by mass of a polycarboxylate water-reducer, 1-5 parts by mass of a surfactant, 5-40 parts by mass of an early strength agent, 2 or less parts by mass of an air entraining agent, and 20-100 parts by mass of water. The preparation method of the compound concrete admixture comprises the following steps: processing a polycarboxylate water-reducer mother liquor to prepare a solution, mixing the polycarboxylate water-reducer solution with the early strength agent, the surfactant, the air entraining agent and water according in proportion, and uniformly stirring. The application of the concrete admixture is realized through the following steps: stirring the concrete admixture and standard sand; taking cement and water, and carrying out low-speed uniform mixing; mixing the above two materials, carrying out low-speed stirring, then carrying out high-speed stirring, intermediately stopping, and then continuously carrying out high-speed stirring; and adding the finally obtained mixture into a mold, and maintaining, wherein the addition of the polycarboxylate water-reducer is not greater than 1% of the amount of a cement mortar. The compound concrete admixture has the advantages of simple preparation method, fast effectiveness, wide application range, low cost and good effect.

The invention discloses a reduced shrinkage early strength polycarboxylic acid water reducing agent mother liquid and a preparation process thereof. The water reducing agent mother liquid is preparedby the free radical copolymerization reaction of a polyether macro-monomer, an anionic active monomer, a cationic active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator;wherein the polyether macro-monomer is isopentenyl polyoxyethylene ether and/or methyl allyl polyoxyethylene ether; the anionic active monomer is acrylic acid; the cationic active monomer is methacrylatoethyl trimethyl ammonium chloride; the shrinkage reducing monomer is an esterification reaction product of a phenyl alcohol or a methyl phenyl alcohol with acrylic acid; the chain transfer agent is 2-methyl-2-propene-1-sulfonic acid sodium salt; and the initiator comprises an initiator system A and an initiator system B, the initiator system A comprises organic hydrogen peroxide and vitamin C,and the initiator system B comprises sodium bisulfite and a ferrous salt. According to the preparation process, different functional monomers are grafted to the high-performance polycarboxylic acid water reducing agent, and the length of the main chain is adjusted, so that the polycarboxylic acid water reducing agent has excellent water reducing rate, and also has early strength and reduced shrinkage.

The invention discloses an early strength composite admixture, which consists of the following components in parts by weight: 8-20 parts of an inorganic salt mixture, 1-8 parts of an organic salt mixture and 75-90 parts of an admixture. Due to the adoption of the early strength composite admixture, the 3h, 8h, 12h and 1d strength of concrete can be enhanced remarkably, long-term strength is not influenced basically, and the working performance and stability of concrete can be improved.

The invention provides a thixotropic agent for a polycarboxylate superplasticizer. The thixotropic agent is mainly prepared from components of raw materials in parts by mass as follows: 0.2-1 part of white carbon black, 3-12 parts of alkali carbonate and 1.5-6 parts of sulfate, wherein the thixotropic agent for the polycarboxylate superplasticizer and a polycarboxylate superplasticizer mother solution are sufficiently and uniformly mixed in water, and the thixotropic type polycarboxylate superplasticizer with excellent thixotropic performance in the precast concrete application process can be obtained. The thixotropic type polycarboxylate superplasticizer containing the thixotropic agent is doped in precast concrete, the thixotropy of the newly blended concrete can be remarkably improved, early strength development is promoted, and the problem that existing polycarboxylate superplasticizers don't have sufficient thixotropic performance in the precast concrete application process is effectively solved.

The invention discloses a polycarboxylate water reducer composite material. The composite material comprises a polycarboxylate water reducer and an activating agent. The activating agent comprises tourmaline powder. The piezoelectric effect and the thermoelectric effect of the tourmaline powder cause the generation of polarization charges, and the generation of polarization charges can reduce the combination of carboxyl end groups of the polycarboxylate water reducer and calcium ions in cement to a certain extent and promote Ca(OH)2 to form crystals, so that the early strength performance is improved.

The invention discloses a calcium silicate hydrate crystal nucleus early-strength polycarboxylic acid water reducer and a preparation method thereof, and the calcium silicate hydrate crystal nucleus early-strength polycarboxylic acid water reducer is prepared from the following components in parts by weight: 480-500 parts of polyether macromonomer, 45-60 parts of silane coupling agent, 45-60 parts of small monomer, 60-80 parts of crystal nucleus solution, 1-3 parts of initiator, 1-3 parts of reducing agent, and 4-6 parts of a molecular weight regulator. According to the invention, the silane group is grafted to the main chain of the polycarboxylic acid water reducer, and then chemical adsorption is generated by utilizing the condensation effect of the hydrolyzed silane group and the hydroxyl group on the surface of the hydrated calcium silicate without occupying the adsorption site of the polycarboxylic acid water reducer. The crystal nucleus early strength type polycarboxylic acid water reducer jointly acts on the surfaces of cement particles through covalent bonds, hydrogen bonds, Van der Waals' force and the like, has a very strong seed crystal effect on cement hydration while giving full play to the water reducing effect, remarkably promotes the early strength development of mortar or concrete, and overcomes the defects in the prior art.

The invention relates to a mineral additive, and belongs to the technical field of concrete additive. The early strength of the mineral additive is higher. The mineral additive is composed of, by weight, 25 to 45 parts of fly ash, 50 to 70 parts of blast furnace slag, 0.5 to 1.5 parts of dihydroxyethyl ethylene diamine, 1 to 3 parts of sodium sulfate, and 1 to 3 parts of calcium oxide. The mineral additive is prepared via taking fly ash and blast furnace slag as main raw materials, so that waste is changed into valuables, environment pollution is avoided, the mineral additive can be used for replacing 15 to 25% of cement at an equal amount, and cost is reduced. Concrete prepared via adding of the mineral additive is high in early strength, so that early strength of concrete is improved.

The invention discloses a method for preparing a lightweight energy-saving building wall material by using high-content steel slag, and solves the problems of low utilization rate, low additional value and low consumption of the existing steel slag. The preparation method comprises the following steps: mixing 40-50 parts of steel slag, 10-20 parts of clinker, 0-20 parts of blast furnace slag, 40-50 parts of fly ash and 5 parts of desulfurized gypsum powder; performing mixing, adding 0.02-0.05% of a grinding-aid early strength agent, and performing fine grinding; adding 0-2% of reinforcing fibers into the mixture after fine grinding; mixing with foaming slurry, and adding a water reducing agent; after uniform stirring, pouring the mixture into a mold; curing the test piece for 1 day under the condition of constant humidity of 30 DEG C, performing demolding, performing curing for 3-6 days under the condition of constant humidity of 35-65 DEG C, and performing natural curing for 28 days to prepare the qualified light energy-saving wall material. The solid waste utilization rate can reach 90%, and the steel slag utilization rate can reach 42.5% or above.

The invention discloses a modified grinding-aiding early strength agent for steel slag as well as a preparation method and an application method of the modified grinding-aiding early strength agent, and relates to the field of steel slag grinding aiding. The modified grinding-aid early strength agent comprises (a) 60%-75% of ester compounds based on the total weight of the modified grinding-aid early strength agent; (b) 5%-15% of polyacrylic acid based on the total weight of the modified grinding-aid early strength agent; (c) 10%-35% of alcohol amine and acrylic acid monomers based on the total weight of the modified grinding-aid early strength agent, the preparation method comprises the following steps: adding water into alcohol amine and acrylic acid, uniformly mixing, heating while stirring, reacting at 60-80 DEG C for 3-4 hours, and cooling the solution to room temperature to obtain the modified grinding-aiding early strength agent which is applied to grinding of a gel material with high doping amount of steel slag, so the problems of low grinding efficiency of an existing grinding aid, low activity of the steel slag in the early stage, complex synthesis process, high cost and the like are solved. The preparation process is simple, the raw material cost is low, the finished product quality and performance are stable, the use effect is good, and the 7d strength increase is greater than or equal to 30%.

The invention discloses an early-strength functional monomer and a preparation method thereof, and an early-strength polycarboxylate superplasticizer and a preparation method thereof. The early strength functional monomer is prepared by the following steps: (1) adding an aminoazo compound and unsaturated alcohol into a reaction container in proportion, and stirring until the azo compound is completely dissolved; (2) adding a polymerization inhibitor and a catalyst into the reaction container, gradually heating to 100 DEG C, and carrying out reflux reaction for 5-8 hours; and (3) after the reaction is finished, cooling to 40 DEG C, neutralizing with a sodium bicarbonate solution until the liquid is neutral, extracting with water three times, recovering an organic phase, drying with anhydrous sodium sulfate for 12 hours, filtering, and distilling to obtain the ester early strength functional monomer. The early-strength polycarboxylate superplasticizer containing the early-strength functional monomer can remarkably improve the early strength of concrete without influencing the later strength in a normal environment, can reduce the viscosity of the concrete and improve the water retention property of the concrete, and is wide in application range and beneficial to popularization.

The invention belongs to the technical field of building material preparation, and particularly relates to a polycarboxylic acid polymer, a preparation method and application thereof. The method comprises the following steps: (1) adding a polymerization inhibitor and part of unsaturated carboxylic acid into molten unsaturated polyether to form a mixed solution A; (2) preparing a mixed solution B from an esterification monomer and the residual unsaturated carboxylic acid; and (3) adding the mixed solution B into the mixed solution A, and performing bulk polymerization under the action of an initiator to obtain a polycarboxylic acid polymer, wherein in the step (3), inert gas is introduced in the early stage of the reaction, oxygen is introduced in the middle stage of the reaction, and inert gas is introduced in the later stage of the reaction. According to the invention, when the method is used for preparing the polycarboxylic acid polymer, the viscosity of a reaction system can be well controlled, the reaction rate is improved, the whole reaction process is stable, the molecular weight of the obtained polymer is narrow, and the effective content is increased; and the polycarboxylic acid polymer is used as a cement grinding aid, so that the grinding aid has good grinding aiding effect, water-reducing rate and early strength performance, and a solvent does not need to be added in the use process.

The invention belongs to the technical field of concrete admixtures, and discloses an early-strength type polycarboxylate superplasticizer and a preparation method and application thereof. The early-strength type polycarboxylate superplasticizer comprises a structural unit A shown in the formula I, a structural unit B shown in the formula II and a structural unit C shown in the formula III. Base on the total weight of the early-strength type polycarboxylate superplasticizer, the weight content of the structural unit A is 76-96%, the weight content of the structural unit B is 0.8-12%, and the weight content of the structural unit C is 0.8-12%. The early-strength type polycarboxylate superplasticizer is high in early strength performance and suitable for the field of early-strength type concrete. (The formulas are shown in the description.).

The invention belongs to the technical field of concrete and specifically relates to admixture concrete. the admixture concrete comprises the following raw materials (by weight): 100 parts of cement,30-35 parts of fly ash, 30-35 parts of blast furnace slag, 14-16 parts of ceramic waste, 30-35 parts of broken stone, 35-40 parts of waste concrete, 1-5 parts of an additive, and 10-30 parts of a lightweight filler. According to the admixture concrete, fly ash, blast furnace slag and other industrial waste residues can be utilized to avoid environmental pollution. In comparison with common concrete, the admixture concrete has the following advantages: use amount of cement is reduced; costs are reduced; and early strength performance of concrete is improved.

The invention discloses a preparation method of monomer-terminated amine ether for synthesizing an early-strength polycarboxylate superplasticizer. The method comprises the following steps: (1) synthesizing block monomer amine ether; (2) refining the block amine ether; and (3) preparing monomer-terminated amine ether. The method provided by the invention has simple process control, stable productstructure and excellent product performance. In the method, a one-step synthesis method different from conventional synthesis methods of alcohols, amine initiators and epoxides is adopted, and throughsynthesis and refining of EO-PO-EO type specific block amine ether and a key technology for terminating amine ether, nitrogen element is introduced into a final polycarboxylate superplasticizer and aprimary hydroxyl group is eliminated through terminating. The polycarboxylate superplasticizer synthesized by the method not only improves an early strength function, but also appropriately reduces an air entraining content, thus further expanding the application of the polycarboxylate superplasticizer in the field of concrete.

The invention discloses a preparation method of a concrete early strength agent. The early strength agent is prepared from, by weight, 20-30 parts of CaO, 15-25 parts of Al2O3, 3-5 parts of TiO2, 4-6 parts of Fe2SO4, 10-15 parts of silicon micro-powder, 15-20 parts of fluorite powder, 0.5-0.7 parts of Y2O3, 1-3 parts of Li2CO3, 0.1-0.3 parts of NaCl and 0.1-0.3 parts of KCl. The preparation method comprises the following steps: carrying out ball milling on above raw materials, calcining the ball-milled raw materials at 800-900 DEG C, and carrying out ball milling on the calcined raw materials and calcium and aluminum hydrotalcite to obtain the concrete early strength agent. The concrete early strength agent has the advantages of good early strength effect, high strength and low temperature low, and is a concrete additive with good prospect.

The invention relates to a nano-micron composite concrete powder early strength agent and a preparation method thereof. According to the designed and prepared nano-micron composite concrete powder early strength agent, the performance advantages of nano particles and micron particles are combined, the early strength agent is well dispersed in concrete by means of the form effect of fly ash particles, and the early strength effect of a nano crystal nucleus early strength agent is fully exerted; the defects that a nanocrystal nucleus early strength agent suspension system is inconvenient to transport and use, poor in stability and the like are overcome, the early strength of the concrete can be greatly improved, and the acceleration of the secondary hydration reaction of the fly ash is also beneficial to the increase of the later strength.