Mix design for thermal insulation concrete using waste coal gangue as aggregate

Abstract

The purpose of this paper is to prepare a new type of thermal insulation concrete (TIC) which possesses good bearing capacity with excellent thermal insulation. An orthogonal experimental design method was used in this paper to study the influence of the substitution ratio of CG and the contents of GHB, NS and UFS on the compressive strength of concrete, thermal conductivity coefficient, construction performance, and dry density. Test results show that the comprehensive strength of concrete reaches the optimal when the substitution ratio of CG is 30%, the GHB content is 134 kg/m³, the proportions of NS and UFS are 0.4% and 5% of binding material amount, respectively. For the optimal mix proportion, the thermal conductivity coefficient and compressive strength of the concrete are 0.41 W m⁻¹ k⁻¹ and 37.7 MPa, respectively.

Keywords:

• Thermal insulation concrete
• Glazed hollow bead
• Coal gangue
• Nano-silica
• Orthogonal experimental design method