Special admixture for shotcrete

Abstract

The invention discloses an admixture special for shotcrete. The admixture special for shotcrete is prepared from the following raw materials in parts by weight: 800 to 900 parts of superfine silicon powder, 50 to 100 parts of a super-plasticizing powder agent, 2 to 5 parts of a sodium polyacrylate adhesive, 0 to 0.05 part of a polysiloxane surfactant, 0 to 6 parts of a powder slump retaining agent, 0 to 4 parts of sodium gluconate, 0 to 100 parts of aluminum sulfate and 0 to 100 parts of sodium hydroxide. The invention discloses application of the special admixture for shotcrete in shotcrete construction. The strength and the binding power of each age are improved; the springback rate of shotcrete is reduced; concrete can be normally sprayed in the water-rich area; achievements reach the domestic leading level; the admixture special for shotcrete can be directly applied to tunnel primary support construction; a new technical way is opened up for primary support construction, experienceworthy of reference is provided for concrete construction under more complex geological conditions, meanwhile, for engineering parts with high requirements on concrete performance, great economic benefits can be brought by using the admixture special for shotcrete, and for shotcrete, the spraying time is shortened.

Description

technical field [0001] The invention relates to the field of concrete, and belongs to the technical field of tunnel and underground engineering construction technology maintenance, operation and maintenance and disaster prevention technology, and is specifically a special admixture for sprayed concrete. Background technique [0002] According to a large number of survey data and statistics, the pass rate of shotcrete is low, the consumption rate of shotcrete is generally 250% to 300% of the design volume, the excess consumption rate is 150% to 200%, and the consumption rate of water-rich areas is generally 410% to 625%. The excess consumption rate is between 350% and 550%. Judging from the results of vigorously promoting wet shotcrete in China in recent years, the quality of shotcrete is related to the success or failure of project construction, and has a great impact on safety, quality and cost. However, due to the late start of wet spraying concrete in my country, the low ...

AI Technical Summary

Problems solved by technology

[0004] The patent document of the patent application number 201210003536.X is improved by controlling the ratio of sand and gravel and adding sodium metaaluminate accelerator, high activity metakaolin, polycarboxylate water reducer or naphthalene sulfonic acid formaldehyde condensation product water reducer. The performance of sprayed concrete, and the effect is only limited to increasing the strength and reducing pollution, and has no effect on the bonding ability, reducing cracks, compensating shrinkage, and slumping time limit, and cannot fully improve the performance of shotcrete;

[0005] 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