多固废协同强化混凝土力学性能与微观结构分析

Analysis on Mechanical Properties and Microstructure of Multi-solid Waste Synergistic Reinforced Concrete

针对工业固废大量堆放的难题,采用矿渣粉、磷石膏、钢渣粉免烧研制出一种多固废胶凝材料,并设计制备出多固废协同强化混凝土,强度等级为C30~C50。通过材性试验和微观分析,探明了其基本力学性能和水化机理。结果表明,C50多固废混凝土28 d立方体抗压强度和弹性模量分别为53.2 MPa和3.58×10^(4)MPa;C50多固废混凝土120 d的收缩率平均为224.4(10^(-6)),具有较好的体积稳定性;多固废协同强化混凝土的水化产物主要为C-S-H和AFt,C50多固废混凝土28 d的微观结构致密,有利于提高其后期强度。

In order to solve the problem of large-scale accumulation of industrial solid waste,this paper used slag powder,phosphogypsum,and steel slag powder to develop a multi-solid waste cementitious material without burning,and designs and prepares multi-solid waste synergistic reinforced concrete with a strength grade of C30~C50.Through material properties tests and microscopic analysis,its basic mechanical properties and hydration mechanism were ascertained.The results show that the 28-day cubic compressive strength and elastic modulus of C50 multi-solid waste concrete are 53.2 MPa and 3.58×10^(4)MPa respectively.The average shrinkage rate of C50 multi-solid waste concrete in 120 days is 224.4(10^(-6)),which has good volume stability.The hydration products of multi-solid waste synergistic reinforced concrete are mainly C-S-H and AFt.The microstructure of C50 concrete for 28 d is dense,which is conducive to improving its later strength.