中文摘要：

纤维增强水泥基复合材料（FRCC）拉伸本构关系模型是纤维混凝土结构设计的基础和关键.本文在对纤维-基体界面粘结强度进行科学评定的基础上,推导了FRCC拉伸开裂面上纤维桥联应力,建立了FRCC的拉伸本构关系模型.比较了两种不同强度等级FRCC的拉伸应力-裂缝张口宽度的模拟曲线和试验曲线,结果显示吻合性较好;利用该模型开展了纤维尺寸参数（长度、直径）复合效应对拉伸应力-裂缝张口宽度曲线的影响分析,为纤维尺寸参数的优化选择提供了理论依据.该模型对实现FRCC性能设计和结构工程应用具有重要的意义.

英文摘要：

Tensile constitutive model of fiber reinforced cementitious composites （FRCC） is critical for designing con- crete structure. Post-crack tensile behavior of FRCC was analyzed and a bridging stress-crack opening relationship of FRCC was presented based on scientific evaluation of interfacial bonding strength between fiber andmatrix. Then, tensile constitutive model of FRCC was established. To calibrate the model, tensile tests of FRCC with different strength grades were conducted experimentally. It was demonstrated that the predicted tensile stress-crack mouth opening width curve fitted well with that of experimental results. Furthermore, a parametric study, the effect of fiber size on the tensile stress and crack mouth opening width was carried out, which provided a theoretical basis for optimization selection of fiber size parameters. Therefore, it is of significance that the mode/can be applied in tailoring tensile properties and structure applications of FRCC.