摘要
为了研究钢纤维掺量和种类对超高性能混凝土(Ultra-High Performance Concrete,UHPC)拉伸性能的影响,采用单轴拉伸试验方法测试狗骨头型试件,得到UHPC的单轴拉伸应力-应变曲线和单轴拉伸特征参数,并观测了UHPC试件的裂缝情况。试验结果表明:随着钢纤维体积掺量的提高UHPC试件的应力应变特性会由应变软化转变为应变硬化,试件也由脆性破坏转变为韧性破坏,抗拉强度、拉伸变形能力和单位体积能量吸收能力也会逐渐提高,其中单轴抗拉强度最高可达14.4 MPa,且单位体积能量吸收能力越高UHPC的应变硬化特性越明显,裂缝控制能力越强;当钢纤维掺量和长径比相同时,端钩型钢纤维对UHPC的韧性提高要好于平直型钢纤维;当钢纤维掺量和形状相同时,在一定范围内的钢纤维长径比越大,UHPC的拉伸变形能力和单位体积能量吸收能力越高,UHPC的应变硬化特性越明显。
In order to study the influence of steel fiber volume content and types on the tensile property of ultra-high performance concrete(UHPC),the uniaxial tensile stress-strain curve and uniaxial tensile characteristic parameters of UHPC were obtained by testing the dog bone specimen,and the crack form of UHPC specimen was also observed.The experimental results showed that the stress-strain characteristics of UHPC specimens would change from strain softening to strain hardening with the increase of the volume content of steel fiber,and the specimens would also change from brittle failure to ductile failure.As the volume content of steel fiber increased,the tensile strength,tensile deformation capacity and energy absorption capacity per unit volume of UHPC specimens would also gradually increase,the uniaxial tensile strength was up to 14.4 MPa,and with the improvement of energy absorption capacity per unit volume,the strain hardening characteristic of UHPC was more obvious,and the fracture control ability was also stronger.When the content of steel fiber and the aspect ratio were the same,the toughness of hooked end steel fiber to UHPC was better than that of flat straight steel fiber.When steel fiber volume content and shape were the same,the greater the length-diameter ratio of steel fiber,the higher the tensile deformation capacity and energy absorption capacity per unit volume of UHPC,and the more obvious the strain hardening characteristics of UHPC within a certain range.
作者
杨文
谢昱昊
毕耀
罗遥凌
闫欣宜
高育欣
YANG Wen;XIE Yuhao;BI Yao;LUO Yaoling;YAN Xinyi;GAO Yuxin(China West Construction Academy of Building Materials,Chengdu 610094,China)
出处
《混凝土》
CAS
北大核心
2022年第5期37-42,47,共7页
Concrete
基金
中国住房和城乡建设部研究开发项目(K2019248)
中建股份科技研发计划资助(CSCEC-2019-Z-24)
中建西部建设股份有限公司科技研发计划资助(ZJXJ-2019-13)。
关键词
超高性能混凝土
拉伸应力应变
钢纤维掺量
钢纤维种类
ultra-high performance concrete
tensile stress-strain
steel fiber volume content
steel fiber volume types
