Influence of activated coal gangue powder on performance of coal gangue coarse aggregate concrete

Abstract

Abstract: Activated coal gangue powder (CGP) was prepared by thermal activation method, which was mixed with coal gangue coarse aggregate (CGA) as mineral admixture to form coal gangue coarse aggregate concrete. The effects of CGP content on the pore structure and microstructure of concrete with different gangue coarse aggregate replacement rates were studied by mercury injection, nitrogen adsorption and scanning electron microscopy. The results show that the compressive strength of coal gangue coarse aggregate concrete is affected by different CGP content and CGA replacement rate. When CGP replacement rate is 15% and CGA replacement rate is 100%, the compressive strength of all coal gangue coarse aggregate concrete increases the most compared with the reference group. The addition of CGP reduces the chloride ion diffusion coefficient of coal gangue coarse aggregate concrete and improves the chloride ion permeability resistance of specimens. CGP can reduce the concentration of alkali ion in the hydration system, promote the hydration reaction of cement clinker, and increase the harmless holes, and optimize the internal pore structure of coarse aggregate concrete with coal gangue.

Key words: coal gangue, activation, compressive strength, chloride ion migration coefficient, pore structure

CLC Number:

TU528

YAN Jie, SHAN Dou-dou, WANG Xiao-tian, YU Xu-tao, LIU Xing-long, XIE Jun. Influence of activated coal gangue powder on performance of coal gangue coarse aggregate concrete[J]. Journal of Lanzhou University of Technology, 2024, 50(1): 139-145.

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