Polycarboxylate superplasticizer meeting requirement for 620-m ultrahigh pumping of self-compacting concrete and preparation method of polycarboxylate superplasticizer

Abstract

The invention provides a special polycarboxylate superplasticizer meeting a requirement for 620-m ultrahigh pumping of self-compacting concrete and a preparation method of the special polycarboxylate superplasticizer. For preparation of every 1,000 g of the polycarboxylate superplasticizer, components of raw materials comprise 160-180 g of polyether macromonomers A, 7-19 g of unsaturated carboxylic acid and derivative monomers B of unsaturated carboxylic acid, 4-25 g of unsaturated carboxylate ester and derivatives C of unsaturated carboxylate ester, 0.8-1.3 g of an initiator, 0.3-3.7 g of a chain transfer agent, 0.2-0.4 g of ascorbic acid and 800 g of water. With application of molecular design theories and correlation theories of water solution free radical polymerization as well as introduction of ester groups, the prepared polycarboxylate superplasticizer is enabled to have better fluidity keeping capacity; the polycarboxylate superplasticizer prevents harmful substance emission in a production process, is free of any by-products causing pollution, further, the raw materials have extensive sources and are easy to obtain and low in cost, and a production technology is simple and easy to control. The polycarboxylate superplasticizer has higher water-reducing rate and good slump retaining and water retaining performance, thereby being capable of effectively solving problems of water seeping under pressure, pumping loss and concrete workability loss which are probably produced during ultrahigh pumping of the self-compacting concrete.

Description

technical field [0001] The invention belongs to the technical field of building materials, and specifically relates to a special polycarboxylate water reducer meeting the requirements of 620-meter ultra-high pumping self-compacting concrete and a preparation method thereof. Background technique [0002] As a product of the combination of industrialization and urbanization, skyscrapers originated in the United States and have now spread all over the world. Skyscrapers are generally considered to be the ultimate symbol of urban development and urban economic power, and they have significant positive significance in promoting intensive use of land, forming urban agglomeration effects, enhancing the image of urban landmarks, expanding the vertical and horizontal space of the city, and promoting the interaction of spatial landscapes. At the same time, since the beginning of the new century, the height of the tallest building in the world has been continuously refreshed, and the a...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the technical problems of the existing ultra-high pumping self-compacting concrete, such as easy segregation of concrete, difficulty in pumping due to excessive viscosity, large loss of fluidity, and easy plugging of pipes, etc.