Alkali-free liquid setting accelerator for spray concrete

Abstract

The alkali-free liquid setting accelerator for spray concrete is compounded with aluminum sulfate 40-70 wt%, magnesium sulfate in 5-50 wt% of the aluminum sulfate, alcohol amine 2-10 wt%, stabilizer 0-10 wt%, defoaming agent in 0-10 wt% of the stabilizer, glycerin 0-1 wt%, and water for the rest. The present invention has excellent cement adaptability, and can provide excellent early strengthening performance and spray construction performance even if to difficult cement with lower C3A content, such as modified cement.

Description

technical field [0001] The invention relates to an accelerator for cement-based materials, in particular to a liquid alkali-free accelerator for shotcrete. Background technique [0002] Shotcrete construction has many advantages that cannot be compared with ordinary formwork concrete, and has become a very important and necessary measure in modern underground engineering. Shotcrete must harden and set extremely quickly, which is achieved by adding accelerators to the concrete at the nozzle. Accelerators for sprayed concrete are very different from those used in ordinary concrete, generally including substances such as alkali metal hydroxides, carbonates, aluminates and silicates, because these substances have Although strong alkali can meet the requirements of shotcrete, it also brings many problems. For example, there are disadvantages such as strong corrosion, large dust, high rebound rate, poor concrete impermeability, and obvious strength reduction in the later stage. ...

AI Technical Summary

Problems solved by technology

However, for some C 3 Difficult cements with lower A content, these materials are difficult to meet the requirements of shotcrete

In this case, even if the setting time of concrete can be shortened by increasing the dosage, it still cannot provide enough early strength to ensure the safety of the project.