Research on Correlation Between Microstructure and Mechanical Properties of Low Strength Recycled Concrete
In order to improve the resource utilization of recycled concrete and meet the requirements of basic engi-neering applications,under the condition of only considering the density,water absorption and moisture content and crushing index of recycled aggregate,the design method of recycled coarse aggregate concrete mix ratio is used to con-figure low-strength recycled concrete.Combined with slicing method and SEM scanning electron microscopy,the pore structure changes and micromorphology of recycled concrete are observed,and the effects of water-to-adhesive ratio,wa-ter reducing agent and fly ash on the internal structure of low-strength recycled concrete are analyzed.It is found that when the water-to-adhesive ratio decreases,the compactness of the internal structure of recycled concrete is improved,the density between flocculent C-S-H is higher,the proportion of harmful pores is reduced,and the compressive and splitting strength is improved.When the content of water reducing agent increases,the content of calcium vanadium(AFt)increases,and the internal structure is more dense.Fly ash has a negative impact on the compressive resistance and splitting strength of recycled concrete,reduces the adhesion between C-S-H and recycled aggregate,increases the in-ternal porosity and the slump,which can reduce the economic cost.
low strengthmix ratio design of recycled coarse aggregatemicrotomySEMporosity
NETL
NSTL
万方数据
维普
