Preparation and performance study of fly ash modified solid waste cementitious powder
Two types of solid waste,carbide slag and fly ash,were used as the main raw materials to prepare solid waste cementitious powders with different fly ash dosages.The influence of fly ash doping ratio on the hy-dration process,microstructure,failure morphology,and mechanical properties of cementitious powder was studied.The results showed that the addition of an appropriate amount of fly ash accelerated the consumption of cement clinker and increased the hydration reaction rate of the cementitious powder.At the age of 28 d,when the content of fly ash was 30wt％,the number of pores in the cementitious powder was the least and the struc-tural density was the highest.The failure morphology of the cementitious powder during the stress process was similar,and the cracks were strip cracks from top to bottom,and there was a collapse phenomenon in the upper part.As the doping amount of fly ash increased,the setting time of the cementitious powder gradually in-creased,the fluidity and chemically bound water content continue to decreased,and the compressive strength and maximum stress changes first increased and then decreased.At the age of 28 d,when the doping amount of fly ash was 30wt％,the maximum compressive strength of the cementitious powder was 14.85 MPa,and the maximum stress at the same strain was 15.70 MPa.Analysis shows that the optimal doping amount of fly ash is 30wt％.
万方数据
维普
