Study on the properties of different biochar to cement paste

Abstract

in order to explore the effect of biochar on cement properties, wheat straw biochar (WS) and rice straw biochar (RS) were pyrolyzed at 300 °C, 500 °C and 700 °C to replace cement with 1% and 2%, and their compressive strength and thermal conductivity were measured. The results showed that the compressive strength of the cement block with biochar increased significantly at 500 °C and 1% cracking temperature, and the compressive strength of the two biochar increased by 31% and 29% respectively The thermal conductivity and thermal diffusivity of two kinds of biochar are decreased, and the thermal insulation performance is improved. The thermal conductivity of rice biochar at 700 °C was the lowest with 2%, and the thermal diffusivity of wheat biochar at 700 °C was the lowest with 2%. It provides a new way to predict the thermal properties of cement-based materials with low thermal conductivity. At the same time, these properties and laws of biochar can also be applied to cement processing, cement thermal conductivity research, material preparation and other practical applications, in order to create better social, economic and ecological benefits.