An alkali-free chloride-free liquid accelerator

Abstract

An alkali-free chloride-free liquid accelerator is disclosed. The liquid accelerator is prepared from following raw materials by weight: 35-55% of polyaluminium sulfate, 5-25% of magnesium oxide, a citrate type salt accounting for 15-30% by weight of the polyaluminium sulfate, 1-5% of an inorganic acid, 1-5% of a stabilizing agent, 1-5% of a defoaming agent and 1-5% of an antichlor, with the balance being water and the total weight percentage being 100%. The alkali content of the liquid accelerator is less than 1%, and the chlorine ion content is less than 1.1%, so that the liquid accelerator belongs to alkali-free chloride-free liquid accelerators. By using the liquid accelerator into concrete, the possibility of alkali-aggregate reactions is largely reduced, steel bar corrosion is prevented, and the durability of concrete is enhanced. The 2.28-d compressive strength ratio is higher than 111%. By using the liquid accelerator into the concrete, the early-stage strength is high, the later-stage strength does not loss lose and is increased, and the stable period is longer than 6 months.

Description

technical field [0001] The invention relates to an alkali-free and chlorine-free liquid accelerator. Background technique [0002] At present, most of the accelerators used in shotcrete produced in China are accelerators with high alkali content. The biggest disadvantages of this accelerator are: first, the durability and service life of concrete are reduced due to the incorporation of a large amount of alkali; The introduction of a large amount of alkali leads to the decrease of the 28d strength of the concrete in the later stage, and practice has proved that the decrease can reach 25-51%. Due to the existence of a large amount of alkaline substances, it will react with the active components in the aggregate inside the concrete, which will cause the alkali-aggregate reaction of the concrete. In addition, because strong alkali is highly corrosive and has a pungent smell, it will seriously affect the personal health of construction workers and cause pollution to the environm...

AI Technical Summary

Problems solved by technology

[0002] At present, most of the accelerators used in shotcrete produced in China are accelerators with high alkali content. The biggest disadvantages of this accelerator are: first, the durability and service life of concrete are reduced due to the incorporation of a large amount of alkali; The introduction of a large amount of alkali leads to a decrease in the 28d strength of the concrete in the later stage, and practice has proved that the decrease can reach 25-51%

In addition, because strong alkali is highly corrosive and has a pungent smell, it will seriously affect the personal health of construction workers and cause pollution to the environment

The second is that these quick-setting agents contain a large amount of Cl. The introduction of chloride ions has serious corrosion to the steel bars. Cavitation and erosion will destroy the internal structure of the concrete, resulting in cracks or cracks on the concrete surface, which will affect the durability and quality of the concrete. service life