Machine-made sand self-leveling concrete

Abstract

The invention discloses machine-made sand self-leveling concrete, which comprises the following components in parts by mass: 100 parts of cement, 40-60 parts of fly ash, 20-40 parts of mineral powder, 0.5-3 parts of polycarboxylic water reducer, 3-8 parts of expanding agent, 0.0004-0.02 parts of anti-foaming agent, 0.0006-0.01 parts of air entraining agent, 3-8 parts of polyacrylamide, 250-350 parts of machine-made sand, 250-350 parts of gravels and 50-80 parts of water. According to the concrete, the working performance of the machine-made sand self-leveling concrete is improved by using flow performance and a thickening effect of the polyacrylamide. The shrinkage of the machine-made sand self-leveling concrete is reduced by combining the water entraining performance of the polyacrylamide with use of the sulphoaluminate type expanding agent. The polyacrylamide is used as a flexible intermediate in hardened concrete, so that the internal stress of the concrete is relieved, and the anti-crack performance of the concrete is improved. No silica fume is used in the concrete, so that the physical health of the operating personnel is guaranteed.

Description

technical field [0001] The invention relates to the field of building materials, in particular to self-leveling concrete prepared with machine-made sand. Background technique [0002] Self-leveling concrete is concrete that can achieve self-leveling and dense molding by its own gravity without vibrating (or slightly vibrating) during pouring. It has good fluidity, segregation resistance, filling and good steel gap passing performance, as well as good mechanical properties and durability, which can reduce and prevent structural segregation and quality accidents due to poor vibration. [0003] When self-leveling concrete is formulated, it mainly solves the contradiction between fluidity and separation resistance, so as to improve the gap passing ability and filling performance of concrete. Therefore, in practical application, self-leveling concrete has high requirements on the particle shape and physical grade of various materials. Compared with conventional self-leveling co...

AI Technical Summary

Problems solved by technology

[0004] However, the use of large amounts of mineral admixtures will further reduce the Ca(OH) in concrete 2 Concentration, if the impermeability of concrete is poor, CO 2 Such environmentally harmful media can easily enter the interior of the concrete, resulting in carbonation of the concrete and corrosion of steel bars.

Moreover, the use of large amounts of mineral admixtures increases the gel content in concrete, increases the shrinkage of concrete to a certain extent, and further increases the risk of concrete cracking