Method for preparing polycarboxylic acid anti-sloughing agent

Abstract

The invention provides a method for preparing a polycarboxylic acid anti-sloughing agent and relates to the technical field of concrete additives. The polycarboxylic acid anti-sloughing agent is composed of, by weight, 7% of prenyl polyoxyethylene ether, 5.5% of maleic anhydride, 16% of acrylamide, 4.5% of hydroxypropyl acrylate, 8.5% of sodium methallyl sulfonate, 3.7% of sodium hydroxide and the rest of water. By combining a polycarboxylic acid anti-sloughing agent and a polycarboxylate superplasticizer, the defect of too large and too fast slump loss of existing polycarboxylate superplasticizers is overcome. The polycarboxylic acid anti-sloughing agent has an obvious anti-sloughing effect. Meanwhile, the polycarboxylic acid anti-sloughing agent can keep flowability of fresh concrete and creates favorable conditions for the use of concrete. In addition, the polycarboxylic acid anti-sloughing agent is combined with a polycarboxylate superplasticizer. As water-reducing rate is raised, strength of concrete is increased, and the disadvantage of low early strength of concrete is also overcome.

Description

technical field [0001] The invention relates to the technical field of concrete admixtures, in particular to a method for preparing a polycarboxylic acid slump-retaining agent. Background technique [0002] The slump-preventing agent is an admixture that can keep the slump of concrete from losing rapidly. The slump-preserving agent mainly plays a role in delaying the hydration and setting of cement to maintain the slump. [0003] The most common problem in cement adaptability is excessive slump loss. At present, there are five main methods to reduce the slump loss of polycarboxylate superplasticizers: (1) composite retarding components; (2) repeated addition of water reducers; (3) post-addition of water reducers ; (4) Sustained release method; (5) Complex reactive polymer copolymer. [0004] Regarding the problem of excessive slump loss, admixture workers usually use polycarboxylate water reducer and retarder to improve the slump retention ability of the water reducer. Ho...

AI Technical Summary

Problems solved by technology

However, the above methods are far from meeting the needs of the project, especially when the transportation distance is long, the problem is particularly prominent

The addition of retarders cannot fundamentally solve the problem of weak slump retention ability of existing polycarboxylate superplasticizers. Excessive addition of retarders will prolong the setting time of concrete, reduce the quality of concrete, and affect construction. schedule. Therefore, it has become a research hotspot of concrete admixtures to develop a kind of anti-slump agent that can keep the slump without loss for a long time and does not affect the later performance of hardened concrete.