Dynamic mechanical properties and constitutive model of specified density concrete reinforced by waste incineration tailings

Abstract

As a green alternative building material for aggregates and admixtures in concrete, domestic waste incineration tailings recently have gained increasing attention from the scientific community, and can improve the sustainability of building materials. This paper studies the performance and mechanism of the specified density concrete reinforced by waste incineration tailings under dynamic impact, focusing on the influence of the dosage (25, 50 and 75 wt%) and the intermediate strain rate (20–80 s-1) of the incineration tailings, and the feasibility of using them as the lightweight aggregate in the specified density concrete. The results show that the failure morphology of the static and dynamic mechanical properties of the specified density concrete (SDC) is similar, and the failure crack passes through the weak interface between the tailing lightweight aggregate and the ordinary aggregate mortar. The addition of incineration tailings is conducive to improving the anti-impact properties of specified density concrete under intermediate strain rate. Due to the internal and external interlocking structure effect of aggregate, the dynamic increase factor (DIF) and energy absorption (ωs) of three types of specified density concrete (SDC-25, SDC-50 and SDC-75) are 79.6%∼99.1% and 1.09 ∼ 1.79 times higher than that of ordinary concrete respectively, and the degree of fragmentation, peak stress and peak strain are significantly improved. The dynamic constitutive equation of specified density concrete with good applicability is proposed and successfully applied to numerical calculation. Considering the engineering performance and potential economic benefits of specified density concrete, incineration tailings can be used as a sustainable and cost-effective substitute for some cement-based materials.