Alkali-free liquid concrete setting accelerator and preparation method thereof

Abstract

The invention relates to an alkali-free liquid concrete setting accelerator and a preparation method thereof. The alkali-free liquid concrete setting accelerator is prepared from the following components in parts by mass: 30 to 60 parts of polyaluminium sulfate, 5 to 20 parts of magnesium sulfate, 5 to 10 parts of calcium formate, 1.0 to 3.5 parts of methylcellulose, 0.8 to 1.5 parts of polyacrylamide, 0.2 to 1.0 part of organic acid, 1 to 3 parts of triisopropanolamine, 0.15-1.08 parts of defoaming agent, 0.5-2.5 parts of hydrofluoric acid, 2 to 6 parts of aluminum hydroxide, 0.5-1.5 parts of 85%-concentration phosphoric acid and 30 to 50 parts of water. The alkali-free liquid concrete setting accelerator has the beneficial effects that the alkali-free liquid concrete setting accelerator provided by the invention does not contain alkali metal ions, and is free of corrosion and pungent smell, stable in quality, good in adaptability, low in mixing amount, high in condensation speed and high in strength.

Description

Technical field [0001] The present invention is the field of concrete exterior agent technology, which involves a alkaline -free liquid concrete steamon agent and its preparation method. Background technique [0002] Speedon agent is an outer agent that makes cement concrete quickly condensed and hardened.It is mainly used in tunnel jet concrete construction and mortar repair construction.The earliest speed condensed agent was the powder-like chorine agent developed by Sika Company in the 1830-40s.In the 1970s, my country began to develop speed coagulants, and has achieved a number of research results, including Red Star I, 711, Yangquan I, Yaoshan Type, 782, etc.Although these powder -shaped speed condensation effects are very good and the price is cheap, due to its high alkali content, it causes serious corrosion to the eyes and skin of the construction workers.High rebound rates and serious dust pollution. [0003] In recent years, due to the high construction efficiency, low ...

AI Technical Summary

Problems solved by technology

Although these powdery accelerators have good coagulation-accelerating effects and are cheap, they cause serious corrosion to the eyes and skin of construction workers due to their high alkali content, and cause a large loss of strength in the later stage, which is likely to cause alkali-aggregate reaction and damage during construction. Problems such as high rebound rate and serious dust pollution

[0003] In recent years, due to the high construction efficiency, low rebound rate and friendly construction environment of wet shotcrete, there is a tendency to gradually replace traditional dry shotcrete. Liquid accelerators for wet shotcrete include alkali accelerators And liquid alkali-free accelerator, from the perspective of its development, the main problems are: high alkali content, large dosage, short stable period, 28d strength ratio less than 100%, etc.

At present, some patent applications are called liquid non-alkali quick-setting agent, but in fact its formula contains a small amount of alkali. Because of the relatively high alkali content of the alkali-containing accelerator, it will bring certain harm to the construction workers. After concrete, it will also cause the loss of concrete strength in the later stage, which will affect the durability of concrete such as impermeability and freeze-thaw resistance.

[0005] 2. Large dosage

[0006] 3. Short stable period

[0008] In addition, liquid alkali-free accelerators often have poor adaptability to cement. Different types of cements are used in combination with them, and the accelerating effects are significantly different.

[0009] Although the research on liquid non-alkali (low) alkali accelerators in my country has developed rapidly and the proportion of engineering applications has also increased significantly, there are still some problems. For example, the dosage of accelerators is concentrated between 3% and 12%, which is relatively traditional. The dosage is too high at about 2%; there is still some instability in the adaptability of some accelerators to different types of cement, admixtures and admixtures; the price is too high