中文摘要：

为研究异形钢纤维对混凝土的增强增韧作用机理,依据Victor Li提出的裂纹面纤维桥联应力公式,考虑钢纤维在基体中的埋置深度、埋置角度以及纤维与基体界面相互作用,提出了单根纤维拔出模型,通过异形钢纤维混凝土梁正截面平衡关系建立了裂纹面纤维桥联应力与截面力的关系。对哑铃形钢纤维在1%、2%、3%三种体积掺量下混凝土梁的弯曲试验数据进行拟合,得到钢纤维混凝土受拉本构关系,应用到截面非线性分析程序后得到的弯矩—曲率关系与试验结果吻和良好。

英文摘要：

A model of fiber pull-out was formulated for the study of strengthening and toughening of deformed steel fiber in ultra-high performance fiber reinforced concrete（UHPFRC）.The model took into consideration fiber embedded length,fiber orientation and interaction between fiber and concrete matrix.Then the relationship was established between fiber bridging stress and force of beam cross section.The tensile constitute model of UHPFRC was built through the data fitting of the flexural test of UHPFRC with the end-flattened steel fiber at the fiber volume ratio of 1%,2% and 3%.The moment-curvature of UHPFRC simulated by the nonlinear section analysis program showed good agreement to the test results.