Experimental study on the influence of temperature on compressive strength of non-spontaneous combustion coal gangue aggregate concrete

Abstract

In Pingxiang mining area of Jiangxi Province, a large amount of non-spontaneous combustion coal gangue is piled up into mountains, which not only occupies the land, but also seriously pollutes the ecological environment. In order to solve this problem and improve the utilization rate of coal gangue, the study of coal gangue without spontaneous combustion in Pingxiang mining area was carried out, and the differences of chemical composition, physical characteristics and thermal activation characteristics of coal gangue were analyzed. On this basis, the coal gangue was used as coarse aggregate instead of some natural stones, and the influence of different temperatures on the compressive properties of coal gangue aggregate concrete was studied. The results show that the compressive strength of gangue concrete is lower than that of ordinary concrete at room temperature. At high temperature, under the influence of secondary hydration of cement and thermal activation of gangue, the compressive strength of concrete test blocks in each group presents an upward trend before 400°C, and reaches its maximum strength at 400°C, among which the mechanical strength of concrete with 30% gangue coarse aggregate is the best. This study provides a basis for the resource utilization of coal gangue in Pingxiang.