Basic Characteristics of Concrete Prepared with Activated Coal Powder instead of Cement

This is an article in the field of ceramics and composites.To explore the feasibility of using coal waste to replace cement for concrete preparation, the activated coal slag powder and coal gangue powder were used to replace cement at a ratio of 0%, 10%, 20%, 30%, and 40% to prepare concrete samples and prepare concrete samples. The slump, compressive strength, flexural strength and high-temperature performance were tested, and the results show that: as the substitution ratio increases, the slump, compressive strength and flexural strength all increase first and then decrease; The optimal substitution ratio is 20%～30%. The early strength growth rate of the activated coal slag powder sample is large; while the long-term strength growth rate of the activated coal gangue powder sample is large. When the water-cement ratio=0.45, the compressive strength of the sample increases first and then decreases with the increase of temperature, and reaches the maximum at 100 ℃; when the water-cement ratio=0.5, the compressive strength of the concrete sample increases with the temperature; the hydration cement structure in the interface area of the activated coal slag powder sample is the most, followed by the control group, and the activated coal gangue powder sample is the least. With the increase in temperature, the pores and cracks on the surface of the sample increased significantly and the degree of fracture of the damaged surface gradually increased.