Application of polycarboxylic high performance water reducer in fine sand concrete

Abstract

The invention provides application of a polycarboxylic high performance water reducer in fine sand concrete. A polycarboxylic water reducer is added into natural sand with a fineness modulus of 1.8 orbelow to make concrete, based on the weight of the polycarboxylic water reducer, 1.6% of a water-retaining component is added, and the water-retaining component is one of CZ-330, hydroxypropyl methylcellulose and W505. The invention applies carboxylic acid to high fineness modulus natural sand to make concrete, can effectively improve the water exudation problem of concrete, and has no significant impact on loss, also can improve the workability, and enlarges the application scope of carboxylic acid in machine-made sand on the concrete market.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to the application of a polycarboxylate high-performance water reducer in fine sand concrete. Background technique [0002] According to the investigation by the inventor, in the actual operation process of many mixing stations, it is reflected that in the process of using carboxylic acid, the concrete has a relatively serious bleeding phenomenon, which in turn leads to the surface of the concrete after pouring, and there is a very serious phenomenon of bleeding. Pipe plugging phenomenon, after research, the reason for this situation is that the mixing station uses natural sand with a low fineness modulus, which is basically around 1.8 fineness modulus. For this, the inventor has carried out a series of tests. The problem of concrete bleeding is solved by adjusting the admixture without changing the mix ratio of the mixing plant. [0003] There are many reasons for the...

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Problems solved by technology

[0003] There are many reasons for the problem of concrete bleeding: 1. Caused by the water-cement ratio, the greater the concrete water-cement ratio, the more free water, the longer the separation time between water and cement, the easier it is for concrete to bleed; concrete admixtures If the dosage is too high, or if the retarding and carboxylic acid slow-release components are too high, it will also cause concrete water retention and segregation; 2. The setting time, fineness, specific surface area and particle distribution of cement will affect the bleeding performance of concrete; 3. Bone Unreasonable gradation of material mixing ratio, resulting in excessive fine particle voids, free water rises, causing bleeding, fine aggregates are too fine, too little cementitious material, resulting in excessive water consumption, low slurry consistency, resulting in free water rising, this It is also a major cause of concrete bleeding

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