Experimental study on mix ratio of new self-insulating concrete

Abstract

It is of great significance to develop wall materials with good thermal and mechanical properties for the wall self-insulation system. In the present paper, a new type of self-insulating concrete has been developed using waste rock wool, vitrified micro beads, cement, mineral powder, sand and gravel as raw materials. The effects of related parameters on concrete strength, thermal conductivity and dry bulk density have been analyzed by orthogonal experiments. The test results show that the content of cementing material and the content of vitrified micro beads are the most important factors affecting the thermal conductivity, compressive strength and dry bulk density of self-insulating concrete; the content of rock wool has a significant effect on the thermal conductivity while has little effect on the compressive strength and dry bulk density; the water-binder ratio has a certain effect on the compressive strength and dry bulk density while has little effect on the thermal conductivity. In the case of the best mix ratio, the average thermal conductivity of self-insulating concrete is 0.195 W/(mꞏK), the average compressive strength is 15.31 MPa, the average dry bulk density is 1637 kg/m³, and the average moisture content is 5.7%. All the above indicators meet the expected performance requirements of self-insulating concrete.