Liquid accelerator for sprayed concrete and preparation thereof

Abstract

The invention relates to a liquid accelerator for shotcrete and a method for preparing the same. The liquid accelerator is prepared from the following components in percentage by weight: 25 to 70 percent of aluminum sulfate, 0 to 8 percent of metal fluoride, 1 to 10 percent of amine substance, 0.5 to 7 percent of pH regulator, 0.01 to 1 percent of thickening agent, and the balance being water. The method for preparing the liquid accelerator comprises the following steps: firstly, dissolving the fluoride into the water; secondly, adding the amine substance to the mixture and heating the solution to a temperature of between 40 and 80 DEG C; thirdly, adding the aluminum sulfate to the solution to perform heat preservation reaction until the solution becomes a uniform liquid; and fourthly, adding the pH regulator and the thickening agent to the uniform liquid and stirring the mixture evenly to finally obtain a uniform liquid substance which is the liquid accelerator for the shotcrete. The liquid accelerator is free from corrosion, has no penetrating odor, has good storage stability so that the phenomena of deposition, crystallization and the like do not appear after the storage of more than 6 months at a temperature of between 0 and 35 DEG C, and does not influence the effect in practice. Using the liquid accelerator with lower mixing proportion (5 to 8 percent), cement can be initially set within 4 minutes and finally set within 10 minutes, and the strength of cement mortar within one day is more than 10 MPa and the storage rate of the strength within 28 days is more than 100 percent.

Description

Technical field

[0001] The present invention relates to a liquid accelerating setting agent for wet spraying cement-based materials, in particular to a liquid accelerating setting agent for sprayed concrete and a preparation method thereof. Background technique

[0002] Shotcrete has many advantages in construction and rock support, and has become a very important and necessary measure in modern underground engineering. In particular, the development of wet-mix shotcrete technology has greatly expanded the scope of use of shotcrete in underground projects. The most important function of liquid accelerator for sprayed concrete is to accelerate the setting of the concrete mixture and improve the early strength, which can increase the thickness of the sprayed layer and shorten the time for spraying the next layer.

[0003] Traditional shotcrete accelerators generally include alkali metal aluminates, carbonates, silicates and other substances, and the dosage is relatively high,...

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