The influence of composite cementitious materials based on recycled fine powders on the mechanical properties and microstructure of concrete
MA Liyuan
LI Ying
Abstract：Two methods were used to prepare concrete specimens by replacing cement with recycled fine powder alone or with recycled fine powder,fly ash and silica fume(their quality ratio is 1∶0.26∶0.17).The influence of composite cementitious materials based on recycled fine powder on the mechanical properties and microstructure of concrete was studied.The results indicate that the addition of 10％recycled fine powder in concrete can improve the compressive strength of concrete at various ages,and the dosage of recycled fine powder should not exceed 20％.The optimal proportion of composite cementitious materials based on recycled fine pow-ders in concrete is 30％.When the proportion exceeds 40％,the later strengthening effect is still very obvious,the 56 d strength of concrete can reach 36.18 MPa.Through SEM,NMR,and TG-DSC analysis,when the substitution rate of composite cementitious mate-rials at 30％,it can effectively exert physical filling and secondary hydration effects,and the pore structure inside the concrete be-comes denser.
Keywords：recycled fine powdercomposite cementitious materialsmechanical propertiesmicrostructure
Publication Date：2025-10-25
Online Publishing Date：2025-11-28(First online date of this platform, not the publication date of the document)
Pages：5( 75-79 )