Preparation method of polycarboxylate superplasticizer for small-slump concrete

Abstract

The invention discloses a preparation method of a polycarboxylate superplasticizer for small-slump concrete. The preparation method comprises the following steps: 1, an ethylene glycol monovinyl polyethylene glycol ether macromonomer, tap water, sodium hydroxide, unsaturated carboxylic acid and 2-acrylamide-2-methylpropanesulfonic acid are added into a four-necked flask one by one, and are uniformly stirred; 2, unsaturated carboxylic acid, tap water and other materials are uniformly mixed to obtain a solution A, and a reducing agent and tap water are uniformly mixed to obtain a solution B; 3,the solution A and the solution B are dropwise added into the four-necked flask at the same time and are reacted; and 4, the pH value of a polymer prepared in step 3 to 5-7 by using an alcohol amine monomer. The polycarboxylate superplasticizer synthesized by adopting the novel polyether in the preparation method improves the wrapping property and winding property of a polyether side chain, so theconcrete has good workability and good flow retentivity, the plasticity and cohesiveness in small-slump concrete are improved, and hysteresis bleeding is avoided; the polycarboxylate superplasticizerhas low sensitivity to the water consumption of concrete, and has a good water-retaining property; and the preparation method has the advantages of simple production process, no generation of wastes,greenness, environmental friendliness, short reaction period, and easiness in realization of large-scale production.

Description

technical field

[0001] The invention relates to the technical field of chemical building materials, in particular to a preparation method of a polycarboxylate water reducer for concrete with small slump. Background technique

[0002] Small slump concrete means that the initial slump is 160-180mm, the concrete has excellent workability, no segregation, no bleeding, moderate viscosity, small slump loss over time, and no obvious hysteresis reaction. , high-performance concrete that is easy to pump for construction. With the continuous improvement of the quality requirements of concrete engineering and the continuous development and progress of construction technology, this type of concrete is used more and more, such as nuclear power projects, prefabricated components, roller compacted concrete and other fields. The water-reducing rate of polycarboxylate superplasticizers commonly used in construction projects is generally high, relying on a slight over-mixing to compensate fo...