高温后混杂纤维混凝土力学性能  

Mechanical properties of hybrid fiber concrete after high temperature

作　　者：李趁趁[1] 刘超伟 魏非凡 赵军[1] LI Chenchen;LIU Chaowei;WEI Feifan;ZHAO Jun(School of Hydraulic and Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《混凝土》2024年第9期94-100,共7页Concrete

基　　金：国家重点研发计划项目(2016YFE0125600);教育部创新团队发展计划(IRT_16R67)。

摘　　要：通过高温后抗压强度和劈裂抗拉强度试验研究了温度、纤维种类、单掺玄武岩纤维掺量、混掺玄武岩纤维(BF)及纤维素纤维(CF)对混凝土力学性能的影响。结果表明:单掺BF或CF均可提升高温后混凝土的抗压及劈裂抗拉强度,相同体积掺量时单掺BF提升效果优于CF。各温度下,随着BF体积掺量的增加,抗压强度与劈裂抗拉强度增加。试验中,单掺玄武岩纤维最佳体积掺量为0.20%,混凝土抗压强度增加率为13.1%~32.6%,劈裂抗拉强度增加率为28.0%~62.4%。各温度下适量混掺BF和CF可以提高混凝土的抗压强度和劈裂抗拉强度,二者具有正混杂效应,比单掺纤维增强效果好。混掺BF体积掺量为0.15%和CF体积掺量为0.10%的B2C1组试件抗压强度和劈裂抗拉强度最高,与普通混凝土相比,抗压强度增加率为14.8%~36.2%,劈裂抗拉强度增加率为31.6%~75.3%。引入协同效应系数分析了玄武岩纤维与纤维素纤维的正负混杂效应,并建立了高温后纤维混凝土的抗压强度和劈裂抗拉强度计算模型,可用于纤维混凝土结构设计及灾后性能评估。The effects of temperature,fiber type,basalt fiber content,mixed basalt fiber(BF)and cellulose fiber(CF)on the mechanical properties of concrete were studied by compressive strength and spliting tensile strength tests after high temperature.The results show that basalt fiber or cellulose fiber can improve the compressive and splitting tensile strength of concrete after high temperature,and the improvement effect of basalt fiber is better than that of cellulose fiber at the same volume content.At each test temperature,the compressive and splitting tensile strength increased with the increase of basalt fiber volume fraction.The optimum volume fraction of single basalt fiber was 0.20%,the increase rate of compressive strength was from 13.1%to 32.6%,and the increase rate of splitting tensile strength was from 28.0%to 62.4%.The compressive strength and spliting tensile strength of concrete can be improved by mixing appropriate amount of BF and CF at each test temperatures,which have positive mixing effect.When the volume fraction of basalt fiber was 0.15%and the volume fraction of cellulose fiber was 0.10%,the compressive strength and splitting tensile strength of B2C1 group were the highest.Compared with ordinary concrete,the increase rate of compressive strength was from 14.8%to 36.2%,and the increase rate of splitting tensile strength was from 31.6%to 75.3%.The positive and negative hybrid effect of basalt fiber and cellulose fiber was analyzed by introducing synergistic effect coefficient,and the calculation model of compressive strength and splitting tensile strength of fiber reinforced concrete after high temperature was established,which can be used for structural design and post-disaster performance evaluation of fiber reinforced concrete.

关 键 词：高温 混杂纤维混凝土 玄武岩纤维 纤维素纤维 力学性能 

分 类 号：TU528.572[建筑科学—建筑技术科学]