白云岩石粉混凝土力学性能试验研究

Experimental Research on Mechanical Properties of Dolomite Powder Concrete

为研究白云岩石粉对混凝土力学性能的影响,采用单掺白云岩石粉等质量取代10%、15%、20%和30%水泥和复掺白云岩石粉-粉煤灰等质量取代20%水泥的方法,对混凝土进行坍落度、扩展度、抗压强度、抗折强度、弹性模量和劈裂抗拉强度试验,并测定其折压比和拉压比。试验结果表明:坍落度和扩展度随石粉掺量增加呈先减后增的趋势,20%掺量时最低;石粉加入会降低抗压强度,15%掺量时强度损失约10%,峰值抗折强度对应石粉掺量为15%;掺量从10%到20%时,混凝土弹性模量和劈拉强度会增大,且折压比、拉压比变大;与单掺比,1∶3复掺白云岩石粉-粉煤灰能保持混凝土坍落度和扩展度,并能提高混凝土抗压强度、抗折强度,1∶1复掺能改善混凝土弹性模量。可见,白云岩石粉掺量在10%~15%之间,复掺比例为1∶3时,混凝土力学性能综合表现更佳。

In order to study the effect of dolomite powder on the mechanical properties of concrete,the method of replacing 10%,15%,20%and 30%cement with dolomite powder and replacing 20%cement with dolomite powder-fly ash was adopted.The slump,expansion,compressive strength,flexural strength,elastic modulus and splitting tensile strength of concrete were tested,and the flexural compression ratio and tensile compression ratio were measured.The test results show that the slump and expansion degrees decrease first and then increase with the increase of stone powder content,and the lowest slump and expansion degrees are obtained with the 20%content.The addition of stone powder reduces the compressive strength;the content is 15%,the strength loss is about 10%,and the peak flexural strength corresponds to the stone powder content of 15%.When the dosage is from 10%to 20%,the elastic modulus and splitting tensile strength,the ratio of bending to compression,and the ratio of tension to compression of concrete all increase.Compared with single mixing ratio,1∶3 mixed dolomite powder-fly ash can maintain the slump and expansion of concrete,and can improve the compressive strength and flexural strength of concrete,1∶1 mixed can improve the elastic modulus of concrete.It can be seen that when the dolomite stone powder content is between 10%and 15%,and the mixed ratio is 1∶3,the comprehensive performance of concrete mechanical properties are better.