超高性能混凝土拉伸力学行为的研究进展

超高性能混凝土(UHPC)是一种具有超高比强度、突出韧性和优异耐久性的水泥基材料,其韧性立足于高强基体和高强纤维之间的高效协同机制基础之上,往往通过拉伸力学行为加以表征。从试验方法、基体和纤维三个角度综述了UHPC拉伸力学行为的研究进展情况,指出UHPC拉伸力学行为宜采用狗骨头状试件进行测试,具有明显的尺寸效应且受加载速率影响;合理优化材料组成、尺寸和分布是提高UHPC拉伸性能的有效途径;纤维种类对UHPC拉伸性能的影响最为显著,提高纤维增强因子和调控纤维分布有利于拉伸性能的提升。最后,从工程应用角度,提出了UHPC拉伸力学行为需要进一步加强研究的建议。

An Overview on Tensile Behavior of Ultra-high Performance Concrete

Highly-effective synergistic interaction between high strength matrix and fiber is the source of outstanding perfor mance advantages of UHPC,a new type of cement-based materials exhibiting ultra-high strength,high ductility,and excellent durability.From the perspectives of testing method,matrix and fiber,this paper reviews the development status of tensile mechanical behavior of UHPC.It also offers some conclusions and opinions of the authors:tensile behavior of UHPC should be studied using dogbone sample and exhibits obvious size effect and strong sensitivity to loading rate;one effective approach to improving UHPC's tensile performance is to carefully tailor its composition and size distribution;fiber type has the most remarkable influence with respect to the tensile performance,which can benefit from both the increase of fiber reinforcing factor and the tailoring of fiber distribution.Finally,some suggestions are proposed for the further study in order to promote engineering applications of UHPC.