不同替代率下玄武岩机制砂混凝土性能影响试验研究  

Experimental study on the influence of manufactured sand from basalt on concrete performance at different replacement rates

作　　者：汪丽娟 乔宏霞[2] 刘志超 宋周义 孙呈鹏 施进儒 WANG Lijuan;QIAO Hongxia;LIU Zhichao;SONG Zhouyi;SUN Chengpeng;SHI Jinru

机构地区：[1]甘肃建投矿业有限公司,甘肃兰州730046 [2]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050

出　　处：《中国矿山工程》2021年第6期54-58,共5页China Mine Engineering

基　　金：国家自然科学基金项目(51168031):西部盐渍土地区基于硫酸盐腐蚀的混凝土耐久性寿命预测研究。

摘　　要：为了研究玄武岩机制砂替代天然砂对高强度混凝土性能的影响,本试验对玄武岩机制砂设置六种不同的替代率(0%、20%、40%、60%、80%、100%),通过对不同替代率混凝土抗压强度、超声波声速和收缩应变进行试验,研究不同的玄武岩机制砂的替代率对高强度混凝土性能的影响。对JZ40收缩应变随龄期的变化数据进行多项式拟合分析,研究混合砂混凝土收缩应变随龄期的变化规律。试验结果表明:玄武岩机制砂替代天然砂作为细骨料会导致混凝土7 d、28 d、56 d抗压强度略微降低,超声波声速作为评价混合砂混凝土密实度的指标时,应该结合更多的影响因素。当替代率小于40%时,机制砂的掺入有利于降低混凝土的收缩变形,四次函数拟合能够较好的反应混凝土的收缩应变随龄期的变化规律。In order to study the influence of replacing natural sand with manufactured sand(M-sand)from basalt on the performance of high-strength concrete,six replacement rates(0%,20%,40%,60%,80%and 100%)are pre-set to test the concrete compressive strength,ultrasonic sound velocity and compression strain at each of these rates and study the influence of different replacement rates on the performance of high-strength concrete.The variation of shrinkage strain over age of the mixed-sand concrete is studied through polynomial fitting analysis on the variation data of JZ40 shrinkage strain over age.The test results show that the M-sand replacing natural sand as fine aggregate can lead to a slight reduction in the 7 d,28 d and 56 d compressive strength of the concrete,and when ultrasonic sound velocity is used as an indicator of the compaction of the mixed-sand concrete,more influence factors should be considered.When the replacement rate is less than 40%,the use of M-sand is beneficial to reducing shrinkage of concrete,and quartic function fitting can better reflect the variation of shrinkage strain over age of concrete.

关 键 词：机制砂 替代率 抗压强度 收缩应变 超声波声速 

分 类 号：TU528[建筑科学—建筑技术科学]