Polycarboxylate superplasticizer for machine-made sand concrete

Abstract

The invention discloses a polycarboxylate superplasticizer for machine-made sand concrete. The polycarboxylate superplasticizer comprises a polycarboxylic acid copolymer, a mud-resistant component, a crack-resistant component, an air entraining agent, an antifoaming agent and a retarder. The polycarboxylate superplasticizer is low in mixing amount, and enables the machine-made sand concrete, in particular the machine-made sand concrete containing high amount of mud and powder to achieve excellent initial working performance, long-term slump holding capability, keep the surface of the hardened concrete from cracking, and improve the durability of the machine-made sand concrete.

Description

technical field [0001] The invention relates to the field of building material additives, in particular to a polycarboxylate water reducer for machine-made sand concrete. Background technique [0002] Concrete is one of the most important building materials in contemporary society. It is composed of cementitious materials, aggregates, water and admixtures, and the polycarboxylate water reducer with a comb structure is the most important admixture for the preparation of high-performance concrete. one of the agents. With the vigorous development of large-scale infrastructure construction, the resources of natural sand, the fine aggregate commonly used in concrete, are gradually decreasing, and the pollution and damage to the environment caused by the mining of natural sand are also becoming more and more serious, resulting in catastrophic disasters such as river bursts and embankments. Accidents also occur frequently. For the sustainable development of the environment, the co...

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Problems solved by technology

If water washing is used to remove clay, it will bring about environmental problems such as increased energy consumption, increased water consumption, and sewage treatment, which is contrary to the sustainable development of green concrete

Therefore, a polycarboxylic acid with good shrinkage reduction and improved concrete workability has been developed and applied to machine-made sand concrete to avoid problems such as excessive water consumption, hardened concrete cracking, and poor durability in freshly mixed machine-made sand concrete. Positive to the development of the industry

[0004] CN102659338A discloses a polycarboxylate water-reducer suitable for machine-made sand, which is composed of polycarboxylate water-reducer mother liquor, fatty alcohol sulfonate and polyether polyol. The way of foaming agent and air-entraining agent can improve the working state of concrete, but it cannot solve the problem of high clay content in machine-made sand

CN102250295A adopts the water-soluble radical copolymerization method to obtain a polymer with a molecular weight of 10000-65000, and neutralizes it with alkali, and the obtained concrete superplasticizer can improve the cohesion and workability of freshly mixed machine-made sand concrete, significantly reducing Segregation and bleeding of freshly mixed concrete, the water reducer failed to solve the problems of high initial water demand and poor durability caused by machine-made sand

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