煤矸石细骨料混凝土力学性能研究OA

To promote the resource utilization of coal gangue solid waste and alleviate the shortage of natural river sand re-sources,a 0.15～4.75 mm graded fine aggregate was prepared from Sichuan coal gangue.C30 concrete mix-tures were formulated by replacing natural river sand with the prepared fine aggregate at equal volumes,using replacement rates of 0,10%,20%,30%,40%,and 50%.The cube compressive strength and splitting ten-sile strength of the specimens were measured at curing ages of 7,14,and 28 days through standard test meth-ods,and the effects of replacement rate and curing age on mechanical properties were systematically investi-gated.The results show that both compressive strength and splitting tensile strength decrease continuously with increasing coal gangue fine aggregate content.At 28 days,the compressive strength and splitting tensile strength of the specimens with 50%replacement rate decreased by 26.4%and 29.7%,respectively,com-pared with the control group.For all mix proportions,the strength development over curing age follows a pat-tern of"rapid growth in the early stage and gradual stabilization in the later stage."When the replacement rate does not exceed 20%,the reduction in 28-day splitting tensile strength is limited to within 6.5%,which can still meet the basic tensile performance requirements for general engineering structures.