Screening agent for improving negative effect of clay on cement concrete system of polycarboxylic acid-doped water reducer and using method thereof

Abstract

The invention discloses a screening agent for improving negative effect of clay on a cement concrete system of a polycarboxylic acid-doped water reducer and a using method thereof, wherein the screening agent is mixed from the following materials in parts by weight: 35-55 parts of sodium metasilicate pentahydrate, 30-50 parts of sodium tripolyphosphate, 7-15 parts of polyethylene glycol, 3-8 parts of sodium humate and 5-10 parts of sodium polyacrylate. When the screening agent is used for production of cement paste, cement mortar and concrete, the screening agent of the corresponding mass proportion only needs to be added, so that effect of improving the negative effect of clay on the cement concrete system of the polycarboxylic acid-doping water reducer can be achieved, and working performances such as liquidity, and the like, of the cement concrete system of clay can be effectively improved; and meanwhile, mechanical performances such as strength, and the like, of the system cannot be lowered.

Description

technical field [0001] The invention relates to the field of cement and concrete admixtures, in particular to a shielding agent for improving the negative effect of clay on cement concrete systems mixed with polycarboxylate superplasticizers and a method for using the same. The shielding agent is suitable for cement concrete mixed with polycarboxylate superplasticizers The system contains more mud. Background technique [0002] Aggregate is an important part of concrete, and the mud content is one of the important indicators to measure the quality of aggregate. At present, the production status of concrete raw materials shows that mud is an inevitable component in concrete aggregate. A large number of engineering practices, Scientific research shows that aggregates with silt have adverse effects on concrete performance, especially aggregates with high silt content or exceeding the standard have a significant impact on concrete performance. [0003] Polycarboxylate superplas...

AI Technical Summary

Problems solved by technology

Wang Ziming and others polymerized a linear polycarboxylic acid polymer as a clay resisting agent, which can reduce the influence of clay on polycarboxylate superplasticizers, but the clay resisting agent can only be a polymer with a specific molecular weight and structure , high molecular weight requirements in the synthesis process

The application number is 201010574716.6, and the patent titled "a method for preparing a mud-resistant polycarboxylate superplasticizer" discloses a mud-resistant polycarboxylate superplasticizer, which is compatible with ordinary polycarboxylate water-reducing agents. It has a good anti-mud effect compared with the agent; but its preparation process is complicated, and the range of types of clay suitable for it is not given

Therefore, the researchers proposed to achieve the purpose of improving the negative effect of clay by means of physical compounding. Liu Guodong proposed a Z agent for inhibiting the adverse effects of high aggregate mud content on concrete. It was used together with polycarboxylate superplasticizer Compound use has a certain improvement effect, which can relatively reduce the dosage of polycarboxylate superplasticizer and improve the performance of polycarboxylate superplasticizer; but this method requires a higher dosage of additives, even with polycarboxylate The compounding ratio of the water reducing agent reaches a certain effect of 1:4, and it does not specify what kind of mud it will work on, and the improvement effect of different mud components is different.

Wang Xingang and others have studied a controllable slow-release polycarboxylate superplasticizer, trying to introduce a slow-release agent to preferentially adsorb polycarboxylate superplasticizer and retarder, and then add them to the concrete system, and the clay will first adsorb The retarder protects the polycarboxylate superplasticizer and ensures that the polycarboxylate superplasticizer molecules play a role on the cement particles; but the problem with this method is that the zeolite itself, as a slow release agent, has a strong adsorption capacity, and the polycarboxylate superplasticizer Can the carboxylic acid superplasticizer molecule be removed freely after being adsorbed by it? If the polycarboxylate superplasticizer is not adsorbed by clay but is adsorbed by zeolite, it will also not be able to play the role of water reducing and dispersing

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