A shotcrete containing polymer modified fibers

Abstract

The invention relates to a shotcrete containing modified polymer fibers, comprising the following raw materials: cement, silica fume, natural zeolite rock powder, pebbles, sand, polypropylene fibers, modified polymer crude fibers, water reducing agent, viscose A binder and water; wherein, the modified polymer crude fiber is prepared from a block polymer of polypropylene-polyethylene glycol, and has excellent cohesion to a cement matrix; and the modified polymer The uniformity of the distribution of crude fiber in the cement matrix has also been improved, so that the impact strength, wear resistance and slump retention performance of shotcrete are significantly improved.

Description

technical field [0001] The invention belongs to the field of building materials, and particularly relates to a shotcrete containing polymer modified fibers. Background technique [0002] Shotcrete is a construction method of pouring fine stone concrete by spraying with a pressure spray gun. It is often used for lining tunnel linings, walls, ceilings and other thin-walled structures or linings of other structures, as well as protective layers of steel structures. Shotcrete is to put pre-prepared cement, sand, stones, water and a certain amount of admixtures into a jet machine, and then use high-pressure air to send it to the nozzle and mix with the accelerator, and then spray it to the rock at a high speed. or the surface of concrete. [0003] Generally, shotcrete is usually mixed with a small amount of steel fibers, the main function of which is to toughen and prevent the concrete from cracking during long-term load-bearing or loading. However, steel fibers suffer from hi...

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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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