53results about How to "Has water reducing effect" patented technology

The invention discloses a crystal nucleus concrete early strength agent and a preparation method thereof. 1,000 parts of crystal nucleus concrete early strength agent are prepared from the following raw materials in parts by weight: 100-150 parts of a polymer, 20-50 parts of sodium metasilicate pentahydrate, 60-90 parts of calcium nitrate tetrahydrate and the balance of deionized water. The preparation method comprises the steps of firstly adding the polymer to a three-neck flask, adding the deionized water to form a base solution, putting the flask into a hot water bath, controlling the temperature and stirring; taking the sodium metasilicate pentahydrate, and adding the deionized water to prepare a solution A; taking the calcium nitrate tetrahydrate and adding the deionized water to prepare a solution B; dropwise adding the solution A and the solution B to the base solution at the same rate, carrying out heat preservation on the product, stirring and reacting; and finally quickly cooling a product to a room temperature to obtain the final product, namely the crystal nucleus concrete early strength agent. The crystal nucleus concrete early strength agent is good in performance, is capable of making concrete solidified quickly, is short in demolding time and not easy to collapse and has a certain water reducing effect, and the later strength loss of the concrete is small.

The invention provides a water-reducing composite modified starch thickener, its preparation method and application. The water-reducing composite modified starch thickener of the present invention is after etherification and modification of maltodextrin molecules, and then introducing sulfonic acid groups. The water-reducing composite modified starch thickener of the present invention has a good thickening effect on concrete, significantly improves the workability of concrete, and also has a certain water-reducing effect, showing that it is compatible with water-reducing agents and air-entraining agents. , retarder and other good adaptability.

Provided is a nano seed crystal early strength agent and a preparation method thereof. The method comprises the steps of first preparation of high molecular polymer dispersion liquid, and then the preparation of the nano seed crystal early strength agent; the high molecular polymer dispersion liquid is prepared from, by weight, 100 parts of polyether macromonomer, 2.5-4.5 parts of silane couplingagent, 7.5-12 parts of unsaturated carboxylic acid, 0.4-0.6 part of chain transfer agent, 0.6-1.2 parts of evocating agent and deionized water; the polyether macromonomer is one of prenol polyethyleneglycol monomethyl ether and methyl allyl alcohol polyethylene glycol monomethyl ether; the silane coupling agent is vinyl triethoxysilane, the unsaturated carboxylic acid is one of acrylic acid, methacrylic acid and fumaric acid, the chain transfer agent is mercaptopropionic acid, and the evocating agent is at least one of ascorbic acid and hydrogen peroxide. The invention also provides a preparation method. The agent has obvious early strength effect on concrete, effectively shortens the demoulding time of the concrete, and improves the mold turnover rate and the production efficiency.

The invention relates to the technical field of building materials, in particular to a bleeding-reducing concrete admixture and a preparation method thereof, wherein the preparation method includes the following preparation steps: adding quicklime to the original ready-mixed concrete waste slurry to perform pressure filtration treatment to obtain a pre-mixed concrete admixture. Mixing waste concrete slurry press filter residue; adding the ready-mix waste concrete slurry filter residue and grinding aid into a ball mill for ball milling to obtain ready-mix waste concrete slurry powder; mixing the ready-mix waste concrete slurry powder and pulverized coal The ash is mixed and stirred to prepare the bleeding-reducing concrete admixture. The invention uses the waste cement slurry produced by the ready-mixed concrete in the concrete mixing plant, and uses it as a raw material to prepare an admixture with reduced bleeding performance, which reduces the amount of other admixtures such as silica fume and mineral powder, and reduces the cost of concrete ; At the same time, high-value reuse of waste slurry from mixing plants has good economic and environmental effects, and is in line with the concept of sustainable development.

The invention discloses a preparation method of water-soluble macromolecular surface-grafted modified machine-made sand. The method is characterized by comprising steps as follows: firstly, performing hydroxylation treatment on machine-made sand to obtain hydroxylated machine-made sand, then modifying the hydroxylated machine-made sand with a coupling agent to obtain a coupling-agent-modified machine-made sand, and enabling the coupling-agent-modified machine-made sand, acrylic acid and methyl allyl polyethenoxy ether to be subjected to grafting polymerization through a grafting polymerization reaction to obtain the water-soluble macromolecular surface-grafted modified machine-made sand. The water-soluble macromolecular surface-grafted modified machine-made sand can effectively enhance the workability and the breaking strength of machine-made sand concrete and can be widely applied to building fields of bridges, roads, railways and the like.