高温后沙漠砂混凝土抗压强度恢复试验研究  

Experimental study on the compressive strength recovery of desert sand concrete after high temperature

作　　者：刘海峰 徐文婧[2] 刘一江 徐婷 杨维武 邵蔚 LIU Haifeng;XU Wenjing;LIU Yijiang;XU Ting;YANG Weiwu;SHAO Wei(Xinhua College,Ningxia University,Yinchuan 750021,China;School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学新华学院 [2]宁夏大学土木与水利工程学院

出　　处：《混凝土》2023年第1期154-158,共5页Concrete

基　　金：国家自然科学基金(51368048,11162015);宁夏自然科学基金(2020AAC03044);宁夏大学研究生创新项目(GIP2020065);宁夏大学生创新项目(2020107490012);宁夏大学新华学院重点建设学科。

摘　　要：采用不同替代率沙漠砂制备沙漠砂混凝土,研究其高温后经二次养护抗压性能。通过高温后沙漠砂混凝土抗压强度试验,分析试件质量损失变化及温度、沙漠砂替代率对抗压强度影响;通过二次养护后抗压强度及SEM试验,分析二次养护龄期和方式对沙漠砂混凝土抗压强度和微观结构影响。试验结果表明:随温度升高,沙漠砂混凝土质量损失率逐渐增大,抗压强度逐渐减小;随沙漠砂替代率增加,抗压强度呈先增大后减小趋势;高温后沙漠砂混凝土内部孔洞、微裂缝数量增多,微观结构劣化严重。高温后沙漠砂混凝土经过二次养护,随养护龄期增加,抗压强度恢复率呈先增大,到达峰值后呈下降或持平趋势。Desert sand with different replacement ratios(DSRR)were used to produce desert sand concrete(DSC),and compressive performance after secondary curing due to high temperature was studied.Through the DSC compressive strength test after high temperature,the influence of temperature and DSRR on DSC compressive strength was analyzed.Through the compressive strength test and SEM test after secondary curing,the influence of secondary curing age and method on the DSC compressive strength and microstructure was analyzed.The test results showed that with the increase in temperature,DSC mass loss rate gradually increased,and the compressive strength gradually decreased.With increasing DSRR,the compressive strength first increased and then decreased.After high temperature,the DSC internal pores and cracks were increased,and the microstructure was seriously deteriorated.After high temperature,the DSC underwent secondary curing.With the increase in curing age,it led to an increase in compressive strength,and after reaching the peak,the compressive strength tended to decrease or remain flat.

关 键 词：沙漠砂混凝土 沙漠砂替代率 高温 二次养护 抗压强度 

分 类 号：TU528.01[建筑科学—建筑技术科学]