Abstract: Disclosed are a method for separately preparing light magnesium oxide and calcium oxide by using dolomite and an application thereof in preparation of a calcium-magnesium composite expanding agent. In the method for preparing light magnesium oxide and calcium oxide, based on the difference in decomposition temperature between magnesium carbonate and calcium carbonate during the calcination and decomposition of dolomite and the difference in the weight of the materials after decomposition, the effective separation of magnesium oxide and calcium oxide is realized by a one-step method, thus separately preparing light magnesium oxide and light calcium oxide. The calcium-magnesium composite expanding agent is prepared by using the foregoing light magnesium oxide and calcium oxide. On the one hand, the present invention solves the problem of the limited origin of the light magnesium oxide raw material of the magnesium expanding component in the calcium-magnesium composite expanding agent.

Abstract: Disclosed is a preparation method of a polycarboxylate water reducer having a regular sequence structure. The preparation method of the present invention comprises: performing Michael addition on polyethylene glycol ether acrylate macromonomer A and amino-containing carboxylic acid B for 5-12 hours, then cooling to 0° C., dropwise adding acryloyl chloride slowly and evenly, and further reacting for 12 hours at room temperature to obtain carboxyl-containing polyether macromonomer C; mixing the carboxyl-containing polyether macromonomer C, a small molecular RAFT reagent, an initiator, and water adequately; and holding the polymerization mass concentration at 30%-60% and heating to 60-80° C. in the atmosphere of N2 to react for 2-5 hours to obtain the polycarboxylate water reducer having a regular sequence structure.

Abstract: Embodiments of the invention relate to concrete admixtures, provide a phosphonato block polymer, a preparation method and an application. The method includes: the phosphonato block polymer prepared by copolycondensating an ether-type segment A, a phosphonato segment B, and a third part of aldehyde C. The ether-type segment A is obtained by polycondensating a polyether monomer and a first part of aldehyde C. The phosphonato segment B is obtained by polycondensating a monomer b containing phosphonato, a monomer c, and a second part of aldehyde C in an aprotic weak polar solvent E. By preparing a block polymer using arylalkane as a main chain and using a phosphonic acid or phosphinic acid functional group as an adsorption group, the invention improves the resistance of the block polymer to sulfate and clay interference, and can achieve initial high dispersion of concrete with a low water-cement ratio and decreasing of the system viscosity.

Abstract: Disclosed are a method for separately preparing light magnesium oxide and calcium oxide by using dolomite and an application thereof in preparation of a calcium-magnesium composite expanding agent. In the method for preparing light magnesium oxide and calcium oxide, based on the difference in decomposition temperature between magnesium carbonate and calcium carbonate during the calcination and decomposition of dolomite and the difference in the weight of the materials after decomposition, the effective separation of magnesium oxide and calcium oxide is realized by a one-step method, thus separately preparing light magnesium oxide and light calcium oxide. The calcium-magnesium composite expanding agent is prepared by using the foregoing light magnesium oxide and calcium oxide. On the one hand, the present invention solves the problem of the limited origin of the light magnesium oxide raw material of the magnesium expanding component in the calcium-magnesium composite expanding agent.

Abstract: Disclosed are a highly adaptable viscosity-reducing polycarboxylate water reducer and its preparation method and application. The highly adaptable viscosity-reducing polycarboxylate water reducer is composed of a polymer and water, and the polymer accounts for 30-50 wt %; since the main chain of the polymer contains a hydrophobic benzene ring and hydrophilic amine, the polymer has strong rigidity and good solubility in an aqueous solution, and is rich in two adsorption groups of carboxyl group/phosphono group. The highly adaptable viscosity-reducing polycarboxylate water reducer of the present invention has excellent water-reducing and slump retention properties and is suitable for general construction projects and commercial concrete projects.

Abstract: Disclosed is an amphiphilic multifunctional hybrid nanoparticle. The nanoparticle of the present invention has a detachable hydrophilic organic polymer with both a water-soluble long chain and a hydrophobic long hydrocarbon functional group attached to the surface, wherein the body of the nanoparticle is a silica or an organofunctional group substituted silica or an organofunctional group substituted silicon-oxygen bond network, and the nanoparticle contains a free organosiloxane with hydrophobic long hydrocarbon functional groups and a fatty acid or fatty acid ester or aluminum complex of fatty acid with hydrophobic long hydrocarbon functional groups.

Abstract: Disclosed is a preparation method of a polycarboxylate water reducer having a regular sequence structure. The preparation method of the present invention comprises: performing Michael addition on polyethylene glycol ether acrylate macromonomer A and amino-containing carboxylic acid B for 5-12 hours, then cooling to 0° C., dropwise adding acryloyl chloride slowly and evenly, and further reacting for 12 hours at room temperature to obtain carboxyl-containing polyether macromonomer C; mixing the carboxyl-containing polyether macromonomer C, a small molecular RAFT reagent, an initiator, and water adequately; and holding the polymerization mass concentration at 30%-60% and heating to 60-80° C. in the atmosphere of N2 to react for 2-5 hours to obtain the polycarboxylate water reducer having a regular sequence structure.

Abstract: The present invention discloses a method for preparing a concrete superplasticizer having a phosphorous acid group and a use of the concrete superplasticizer. The concrete superplasticizer having a phosphorous acid group according to the present invention is prepared by free radical copolymerization of a phosphorous-containing monomer A and a polyether macromonomer B. The concrete superplasticizer having a phosphorous acid group obtained in the present invention can effectively improve flowability of concrete and can retain good workability of concrete. The method is simple, economical and effective, and in particular, can be used for commercial mass production.

Abstract: The present invention provides a method for preparing a polymer and a use of the polymer. The resulting polymer is used as a dispersant for an aqueous dispersion of a hydraulic binder and/or a latent hydraulic binder, such that water-reducing rate is improved, and suitable control of air content can be achieved, thereby improving the strength of concrete. The method for preparing a polymer includes polycondensation of a polyether macromonomer A of a specific structure, a monomer B and an aldehyde C to obtain the polymer. The monomer B is phenylsulfonic acid, p-/o-aminophenylsulfonic acid, p-/o-hydroxylbenzoic acid, p-/o-aminobenzoic acid, p-/o-hydroxylphenylsulfonic acid, or a phosphoric acid group or phosphorous acid group-containing monomer of a specific structure. A molar ratio of the polyether macromonomer A and the monomer B is 1:(0.5 to 12).

Abstract: The present invention discloses a phosphorylated polycondensate high-performance water-reducing agent with a phosphorylated melamine derivative, instead of a conventional carboxyl group or sulfonic group, as a main adsorption group. The use of aryl alkoxypolyether as a side chain of the polymer provides a strong steric effect to improve the dispersibility and dispersion-retaining properties of the polymer. A polycondensate high-performance water-reducing agent and a method for preparing the same provided by the present invention have excellent overall performance, high adaptability for current low-grade raw materials of concrete, strong market demands, and vast application prospects. Additionally, the polycondensate has an advanced preparation process provided with the characteristics of industrially scalable production, which offers the prospect of a core technology in the field of water-reducing agent of concrete so as to promote development of the industry.

Abstract: The present invention provides a method for preparing a polymer and a use of the polymer. The resulting polymer is used as a dispersant for an aqueous dispersion of a hydraulic binder and/or a latent hydraulic binder, such that water-reducing rate is improved, and suitable control of air content can be achieved, thereby improving the strength of concrete. The method for preparing a polymer includes polycondensation of a polyether macromonomer A of a specific structure, a monomer B and an aldehyde C to obtain the polymer. The monomer B is phenylsulfonic acid, p-/o-aminophenylsulfonic acid, p-/o-hydroxylbenzoic acid, p-/o-aminobenzoic acid, p-/o-hydroxylphenylsulfonic acid, or a phosphoric acid group or phosphorous acid group-containing monomer of a specific structure. A molar ratio of the polyether macromonomer A and the monomer B is 1:(0.5 to 12).

Abstract: The present invention discloses a method for preparing a concrete superplasticizer having a phosphorous acid group and a use of the concrete superplasticizer. The concrete superplasticizer having a phosphorous acid group according to the present invention is prepared by free radical copolymerization of a phosphorous-containing monomer A and a polyether macromonomer B. The concrete superplasticizer having a phosphorous acid group obtained in the present invention can effectively improve flowability of concrete and can retain good workability of concrete. The method is simple, economical and effective, and in particular, can be used for commercial mass production.

Abstract: Disclosed is a method for testing the self-drying effect of a cement-based material, capable of testing the change in humidity of the cement-based material after the final setting until the Id stage of adding water, so as to reflect the water consumption therein and the self-drying course. In the time period after the final setting of the cement-based material until the 1 d stage of adding water and forming, the dew-point temperature inside the cement-based material is tested, and then the relative humidity inside the cement-based material is calculated using a formula. The present invention can test the change in humidity of the cement-based material after the final setting until the Id stage of adding water, so as to reflect the internal water consumption therein and the self-drying course.

Abstract: Disclosed is a method for testing the setting time of a cement-based material: testing the capillary negative pressure of a non-bleeding cement-based material, with the time at which the capillary negative pressure reaches a threshold value A as the initial setting time, and/or the time at which the capillary negative pressure reaches a threshold value B as the final setting time, wherein threshold value A is 8-10 kPa, and threshold value B is 54-56 kPa.

Abstract: A slump retaining polycarboxylic acid superplasticizer. A weight average molecular weight of the superplasticizer is 20,000-80,000. The slump retaining polycarboxylic acid superplasticizer is prepared by performing polymerization reaction on a monomer A, a monomer B, a monomer C and a monomer D in an aqueous solution in the presence of a redox initiator, wherein a molar ratio of (the monomer A+the monomer B):the monomer C:the monomer D is 1:(3-8):(4-12), and a molar ratio of the monomer A to the monomer B is 1:(1-4).

Abstract: The present invention provides a preparation method of hyperbranched polycarboxylic acid type copolymer cement dispersant, including: Monomer A, B and C undergo a free radical copolymerization in an aqueous medium. The molar ratio of Monomer A, Monomer B and Monomer C conforms to B/A?A?2?10 and C/(A+B?C)?0.02?0.08. Monomer A is expressed by General Formula (1), where, R1 is H or a methyl; X1?O, CH2O, CH2CH2O; m is an integer from 5 to 200. Monomer B is expressed by General Formula (2), where, R2 is H or COOM; R3 is H or CH3 and M is H, Na, K or NH4; Monomer C is expressed by General Formula (3), where, R4 is H or methyl; X2?O, CH2O, CH2CH2O; Y?CH2, CH2CH2, CH(CH3), CH2CH2CH2, CH(CH3)CH2, C(CH3)2 and n is an integer from 5 to 200.

Abstract: Disclosed is a method for testing the setting time of a cement-based material: testing the capillary negative pressure of a non-bleeding cement-based material, with the time at which the capillary negative pressure reaches a threshold value A as the initial setting time, and/or the time at which the capillary negative pressure reaches a threshold value B as the final setting time, wherein threshold value A is 8-10 kPa, and threshold value B is 54-56 kPa.