Sprayed concrete containing high polymer modified fibers

Abstract

The invention relates to a sprayed concrete containing high polymer modified fibers. The sprayed concrete is prepared from cement, silica fume, natural zeolite rock powder, pebbles, sands, polypropylene fibers, modified polymer crude fibers, a water reducing agent, a binder and water. The modified polymer crude fibers prepared from a polypropylene-polyethylene glycol block polymer, and has excellent cohesiveness to a cement matrix; and the distribution uniformity of the modified high polymer crude fibers in the cement matrix is also improved, so that the impact strength, wear resistance and slump loss resistance of the sprayed concrete are obviously improved.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to shotcrete containing high polymer modified fibers. Background technique [0002] Shotcrete is a construction method of spraying and pouring fine stone concrete with a pressure spray gun. It is often used for filling tunnel linings, walls, ceilings and other thin-walled structures or linings of other structures and protective layers of steel structures. Shotcrete is to put pre-prepared cement, sand, gravel, water and a certain amount of admixture into the sprayer, use high-pressure air to send it to the nozzle and mix it with the accelerator, and spray it to the rock at a high speed. or concrete surface. [0003] Generally, shotcrete is usually mixed with a small amount of steel fibers, and its main function is to toughen and prevent the concrete from cracking during long-term bearing or loading. However, steel fibers have the disadvantages of high cost and easy co...

AI Technical Summary

Problems solved by technology

[0004] However, polypropylene coarse fibers also have their unavoidable defects. The main reason is that, on the one hand, the compatibility between polypropylene and cement, the main matrix in concrete, is very poor, which causes the interfacial cohesion between polypropylene coarse fibers and cement matrix. Poor compatibility makes the polypropylene coarse fibers easy to peel off from the original state embedded in the cement matrix, and cannot fully exert its toughening effect; Uneven distribution, so that the part of the cement matrix containing less polypropylene coarse fibers is prone to cracking after being subjected to high-strength loads (Liu Weidong, Research on Engineering Performance of Modified Polypropylene Fiber Concrete, Ph.D. Thesis in 2009 )

The above results in unsatisfactory mechanical properties of shotcrete

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