Study on Collaborative Preparation of Cement Stabilized Materials with "Ternary Solid Wastes" and Their Performance under Dual Excitation Effects

Abstract

Abstract The research of traditional industrial waste in roads is limited to a single waste. To facilitate the application of various industrial solid wastes in pavements. In this paper, a pavement base mixture was prepared collaboratively with "the ternary solid wastes" that formed by steel slag, red mud and electrolytic manganese residues (EMRs) under dual excitation effects, namely alkali and sulfate excitation. Subsequently, a relevant heavy metal curing agent was developed. Afterwards, the physical and mechanical properties of the base mixture were analyzed through (a) 7 d and 28 d unconfined compressive strength tests; (b) 28 d and 90 d splitting and flexural tensile strength tests ; (c)and shrinkage and frost resistance tests. Moreover, the strength formation mechanism of the mixture was explored by combining the X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. In addition, the leaching toxicity of the heavy metals was analyzed by detecting their leaching content. It was revealed that (1) the mixture strength was optimal at the mixing proportion of 3:1:2 (steel slag : red mud : EMRs). (2) The mixture strength was improved owing to the calcium silicate hydrate (C-S-H) and ettringite (AFt) crystals generated from the hydration re-action of the "ternary solid wastes" mixture under dual excitation effects. (3) The heavy metal elements in the mixture could be solidified and leached out just by adding 1% of the heavy metal curing agent composed of Cr (hexavalent), Hg, and V elements, thus, meeting sewage discharge standard.