Composite admixture for shotcrete

Abstract

The invention belongs to the technical field of concrete admixtures, and discloses a composite admixture for shotcrete. The composite admixture is prepared from the following substances in parts by weight: 5 to 20 parts of polycarboxylate superplasticizer, 1 to 5 parts of disodium alcohol ether sulfosuccinate, 2 to 8 parts of tackifier, 1 to 3 parts of ammonium nitrate, 5 to 10 parts of alcohol amine carboxylate, 0.01 to 0.1 part of sodium dodecyl benzene sulfonate, 0.01 to 0.1 part of organic silicon defoamer and 30 to 80 parts of ultrafine fly ash. After the admixture is added, the contact performance of concrete and a spraying surface is good, the problem of serious springback of sprayed concrete is effectively solved, coagulation and solidification of the sprayed concrete can be accelerated, and the strength of the concrete is improved.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures, in particular to a composite admixture for shotcrete. Background technique [0002] Shotcrete is a kind of quick-setting concrete used to strengthen and protect structures or rock surfaces. This technology uses compressed air or other power to mix cement, sand, stones and admixtures in a certain proportion with the help of spraying machinery. The mixed material is sprayed onto the sprayed surface through the nozzle, and the concrete reinforcement material is formed by setting and hardening within a few minutes. Shotcrete is mainly used for spraying reinforcement of mine shafts, tunnels, culverts and other projects. The admixture used is generally a quick-setting agent. Since the inner walls of coal mine lanes, tunnels, culverts, etc. have a lot of water, and the walls of the tunnels are relatively smooth, the bonding force between the shotcrete and the walls becomes smaller, and it i...

AI Technical Summary

Problems solved by technology

The admixture used is generally a quick-setting agent. Since the inner walls of coal mine lanes, tunnels, culverts, etc. have a lot of water, and the walls of the tunnels are relatively smooth, the bonding force between the shotcrete and the walls becomes smaller, and it is easy to drop ash and cause rebound. The ratio is large; and the water-binder ratio increases, which also affects the strength of concrete

[0003] In the patent application number 201811592063.5, an ultrafine admixture is disclosed, which includes the following raw materials, micro silica fume, superplasticizing powder, sodium polyacrylate binder and polysiloxane surfactant, but it exists in concrete curing The phenomenon of water separation during time is serious, and the technical problem of low homogeneity level after curing

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