Polycarboxylate superplasticizer for machine-made sand concrete prestressed component and preparation method of polycarboxylate superplasticizer

Abstract

The invention discloses a polycarboxylate superplasticizer for a machine-made sand concrete prestressed component and a preparation method of the polycarboxylate superplasticizer. The polycarboxylatesuperplasticizer is prepared from the following raw materials in parts by mass: 50-100 parts of polyether macromonomer, 20-40 parts of an ester macromonomer, 5-15 parts of maleic acid-beta-cyclodextrin, 5-15 parts of styrene, 30-60 parts of an acrylic monomer, 10-30 parts of unsaturated phosphate and 5-25 parts of an ammonium cation unsaturated monomer in a free radical polymerization manner so asto prepare a polymer with the molecular weight of 15000-80000; and 0-4 parts of an organic silicon defoamer, 0-10 parts of an early strength agent and 5-15 parts of a sacrificial agent are compounded, and then an alkaline solution is added for neutralization. The polycarboxylate superplasticizer has high tolerance to the stone powder content of machine-made sand concrete, good water reducing andviscosity reducing effects and an early strength function, meets the production requirements of machine-made sand concrete prestressed components in the fields of railways, highways, water conservancyand the like, and in particular, is used for preparing high-strength prestressed components with low water-binder ratios.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a polycarboxylate water reducer for machine-made sand concrete prestressed components and a preparation method thereof. Background technique [0002] Due to the characteristics of seasonal mining of natural river sand and the implementation of the mining restriction policy, river sand resources are seriously in short supply. Using machine-made sand instead of river sand to prepare concrete prestressed components is an effective measure to solve this problem. Compared with river sand, machine-made sand has rough particles, sharp edges and corners, and contains a certain amount of stone powder, which puts forward higher requirements for water reducing agents for concrete prestressed components. [0003] The water reducing agent in concrete precast components should have the characteristics of high water reducing rate, good adaptability, obvious early strength effect, s...

AI Technical Summary

Problems solved by technology

[0004] The stone powder in the machine-made sand has a strong adsorption effect on the polycarboxylate superplasticizer, which reduces its adsorption to cement particles, affects the dispersion effect, and reduces the application effect of the polycarboxylate superplasticizer

As the content of stone powder increases, the dispersibility and water-reducing effect of polycarboxylate superplasticizers drop sharply, or even have no dispersing ability and lose water-reducing effect

Moreover, the lithology of machine-made sand is various, and the stone powder of different lithology has different adsorption capacity to polycarboxylate superplasticizer, and the effect of polycarboxylate superplasticizer will also fluctuate greatly, which will affect the use

Chinese patent CN102659338A "A polycarboxylate superplasticizer suitable for machine-made sand" discloses a polycarboxylate superplasticizer composed of a water reducer mother liquor, fatty alcohol sulfonate and polyether polyol. The Chinese patent "A Concrete Admixture and Its Use in Concrete Containing Manufactured Sand" discloses an admixture made of polycarboxylate water reducer, dipropylamine and sodium hexametaphosphate. For compounding, add functional components on the basis of the original water reducing agent and adjust properly, the applicability is limited

The above-mentioned machine-made sand concrete with low stone powder content can reduce the viscosity to a certain extent, but it cannot effectively solve the problem that the machine-made sand concrete with high stone powder content is viscous and difficult to mix and pour

Images