高温后掺纳米CaCO3混凝土劈裂抗拉性能研究  

Study on Splitting Tensile Properties of Nano-CaCO3Concrete after High Temperature

作　　者：苗生龙[1] 李庆涛 赵园园[1] 胡海波[1] 刘玉田[1] MIAO Shenglong;LI Qingtao;ZHAO Yuanyuan;HU Haibo;LIU Yutian(Xuhai College,China University of Mining&Technology,Xuzhou 221008,China;School of Mechanics&Civil Engineering,China Univ.of Mining&Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学徐海学院,江苏徐州221008 [2]中国矿业大学力学与土木工程学院,江苏徐州221116

出　　处：《三峡大学学报（自然科学版）》2020年第3期68-72,共5页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(51208504);江苏省高等学校自然科学研究项目(17KJB560014);江苏高校“青蓝工程”资助(20200415)。

摘　　要：为研究不同高温后掺纳米碳酸钙(NC)混凝土的劈裂抗拉性能,进行了不同NC掺量(0%、0.5%、1.0%、1.5%、2.0%和3.0%)混凝土的高温试验,对分别采用自然冷却和喷水冷却方式后的NC混凝土进行了加载试验.分析了温度、NC掺量及冷却方式等对混凝土劈裂抗拉强度的影响.结果表明:随着受热温度的增加,NC混凝土的劈裂抗拉强度逐渐降低.在混凝土中添加适量的NC可以改善混凝土高温后的劈裂抗拉性能.不同的冷却方式对NC混凝土劈裂抗拉强度有不同的影响:高温(尤其是400℃以上)后采用喷水冷却的混凝土静置两周后,其劈裂抗拉强度均高于采用自然冷却后的劈裂抗拉强度.同时,800℃后,自然冷却的NC混凝土试块在室内放置两周后多数发生自行坍塌情况,几乎完全丧失强度.研究结果可为进一步开展纳米混凝土高温后的其它力学性能和耐久性能提供参考.For study the splitting tensile properties of concrete mixed with nano-CaCO3(NC)after different high temperatures,the high temperature test of NC concrete with different NC content were carried out.The load tests of concrete after natural cooling and water spraying cooling were tested respectively.The effects of temperature,NC content and cooling methods on splitting tensile strength of concrete were analyzed.The results show that with the increase of heating temperature,the splitting tensile strength gradually decreases.Adding proper amount of NC to concrete is beneficial to improving splitting tensile properties of concrete after high temperature.Different cooling methods have different effects on the splitting tensile strength of NC concrete.After high temperature(especially above 400℃),the splitting tensile strength of concrete with water spray cooling method is higher than that with natural cooling method after being placed for two weeks.The NC concrete specimens heated 800℃by natural cooling mode mostly collapsed after being placed in indoor environment for two week,and almost completely losing strength.The conclusions can provide reference for further development of other mechanical properties and durability of nano-concrete after high temperature.

关 键 词：纳米碳酸钙 劈裂抗拉强度 高温 冷却方式 混凝土 

分 类 号：TU528.1[建筑科学—建筑技术科学]