Durability and Microstructure Characteristics of Coal Gounge Ceramsite Concrete under Freezing-Thawing Action

Authors

  • Bowen Hou, Jisheng Qiu

Abstract

To study pore distribution characteristics and durability of micropore structure of coal gangue ceramsite concrete (CGCC) under freezing-thawing cycles, low-field nuclear magnetic resonance (LNMR) test, nitrogen adsorption test, scanning electron microscope (SEM) test and other tests were used to determine the effect of freeze-thaw cycles on the porosity, relative dynamic elastic modulus (RDM) and capillary adsorption rate of different coal gangue ceramsite (MT) replacement rates (0, 20%, 40% and 60%). In view of the particularity of MT material, the method based on pore size is put forward to distinguish M pores from T pores.Moreover, the causes of freezing-thawing damage of common concrete (OC) and CGCC are analyzed from micro perspective. The result shows that freezing-thawing cycle action could change the microstructure of coal gangue concrete and has obvious influence on its properties. And when the replacement rate is 40%, degradation mitigation performance is optimal. Due to the particularity of MT shape, T pores are dominant in coal gangue concrete matrix, which is different from the microstructure of ordinary concrete and can reduce the structural deterioration caused by freeze-thaw. The research results of this paper can provide reference for the research and application of CGCC in freeze-thaw environment.

Published

2020-10-01

Issue

Section

Articles