早强型固废基胶凝材料硬化体的宏观性能与微观机理

Macroscopic Properties and Microscopic Mechanism of Hardened Early-Strength Solid Waste Based Cementitious Materials

摘要:

基于工业固废协同利用原理，采用氨碱白泥、矿渣、钢渣和脱硫石膏制备了一种早强型固废基胶凝材料（SSC），研究了氨碱白泥对SSC力学性能、微观形貌、水化产物、孔隙结构、水化进程及Cl^-吸附效果的影响。结果表明：氨碱白泥能够加速SSC的早期水化，并显著提高其早期强度；当氨碱白泥、矿渣、钢渣和石膏的质量比为10.0∶49.5∶27.0∶13.5时，SSC胶砂试件的1、28 d抗压强度分别为12.9、44.5 MPa，Cl^-结合率为93%，SSC硬化体的水化产物紧密搭接、填充，形成了密实结构，其28 d龄期的水化产物主要包括水化硅（铝）酸钙凝胶、钙矾石和Friedel’s盐。

Abstract:

Based on the principle of synergistic utilization of industrial solid waste， an early-strength solid waste based cementitious material（SSC） was prepared using soda residue， slag， steel slag and desulfurization gypsum. The effects of soda residue on the mechanical properties， microstructure， hydrated products， pore structure， hydration kinetics and chloride ion adsorption capabilities of the SSC were investigated. The results indicate that soda residue significantly accelerates the early hydration of the SSC and enhances its early-age strength. Specifically， at an optimal mass ratio of soda residue to slag to steel slag to gypsum of 10.0∶49.5∶27.0∶13.5， the compressive strengths of the mortar specimens at 1 d and 28 d are 12.9 MPa and 44.5 MPa， respectively， with a chemical binding ratio of chlorine ion at 93%. Furthermore， the hydrated products within the hardened paste of the SSC exhibit a dense， interlocking and filling structure， with the primary hydrated products at 28 d being calcium silicate（aluminate） hydrate gel， ettringite and Friedel’s salt， which form the foundational strength of the solid waste based cementitious material.