Influence of the substitution rate of fly ash on the properties of multicomponent solid waste-based backfill materials
CHEN Nuo
WANG Ningning
CHEN Xudong
BAO Yijun
Abstract：Using construction and demolition waste,recycled micro powder,and cement as main raw materials,fly ash(FA)is used to replace some cement to prepare multi-component solid waste based backfill material(CLSM).The influence of FA substitution rate on the workability and mechanical properties of CLSM is studied,and its mechanism of action is analyzed by SEM.The results showed that when the FA substitution rate was 30%,the working performance of CLSM was the best,with an initial flowability increase of 37.1%compared to the benchmark group,and the lowest flowability loss rate over time;As the substitution rate of FA increases,the unconfined compressive strength of CLSM gradually decreases at all ages.When the dosage of FA is low,the pore structure is optimized through the synergistic effect of physical filling and volcanic ash activity;When the content of FA is high,the dispersion of hydration products is caused by insufficient cementitious components and delayed activity.
Keywords：construction and demolition wastesolid waste utilizationfly ashbackfill materialrecycled powder
Publication Date：2025-09-25
Online Publishing Date：2025-10-15(First online date of this platform, not the publication date of the document)
Pages：5( 60-63,102 )