中文摘要：

为探究ECC材料受弯性能，对受弯钢筋增强ECC双筋梁正截面进行了理论和试验研究．首先基于平截面假定和材料本构模型，得到各阶段承载力计算方法．然后，通过试验结果与理论结果对比，验证所提出的梁承载力计算方法正确性．最后，基于所提出的理论公式，对ECC材料的抗压强度和抗压应变、抗拉强度和配筋率进行分析，探究其对钢筋增强ECC双筋梁正截面受弯性能的影响．理论分析结果与试验结果吻合良好，说明理论分析模型能够用于预测钢筋增强ECC梁的弯矩-曲率关系．参数分析结果表明：提高ECC抗压强度将大幅改进梁受弯性能；提高ECC极限受压应变可大幅提高梁极限曲率和延性，但对受弯承载力影甚微；ECC抗拉强度对梁受弯性能影响微弱；配筋率的增大可大幅提高梁受弯承载力和刚度，但会降低梁的延性．所提出的理论计算模型和参数分析结果对于钢筋增强ECC梁受弯性能的设计研究具有指导意义．

英文摘要：

In order to investigate the flexural behaviors of engineered cementitious composites （ECC）, theoretical and experimental researches are done on flexural doublereinforced ECC beams. Based on the assumption of the plane section remaining plane in bending and simplified constitutive models of materials, the calculation methods of load carrying capacities for different critical stages are obtained. Then, these calculation methods are demonstrated by comparing the test results with the calculation results. Finally, based on the proposed theoretical formulae, the effects of the compression strength, compression strain and tension strength of ECC, and the reinforcement ratio on the flexural behaviors of double-reinforced ECC beams are analyzed. The calculated and measured results are in good agreement, which indicates that the theoretical model can be used to predict the momentcurvature response of steel reinforced ECC beams. And the results of parametric studies show that the increase in the compression strength of ECC can greatly improve the flexural performance of beams; the increase in the ultimate compression strain can significantly improve the ultimate curvature and ductility, but has little effect on the load bearing capacity of beams. little effect on the flexural The tensile strength of ECC has behaviors of ECC beams. The increase in the steel reinforcement ratio can lead to significant improvement of the load bearing capacity and the stiffness of beams, but a degradation of the ductility of beams. The theoretical model and parameter analysis results in this paper are instructive for the design of steel reinforced ECC beams.