超高强钢筋工程用水泥基复合材料梁受弯计算理论

Theoretical on flexural behavior of ultra high strength rebar reinforced engineered cementitious composites beam

以工程用水泥基复合材料及超高强钢筋的应力-应变本构关系为基础,根据平均应变的平截面假定和梁受拉区ECC不退出工作等假定,建立超高强钢筋ECC梁正截面受弯计算理论,得到了开裂弯矩、屈服弯矩、极限弯矩、界限配筋率和最小配筋率的计算方法。最后,通过文献中的试验结果验证了本文计算理论的合理性。

A new type of reinforced Engineered Cementitious Composites(ECC)beam was proposed with ultra high strength bars,named ultra high strength rebar reinforced ECC beam(UHSRRE).The tensile bearing capacity of ultra high strength reinforcement was expected to be efficiently utilized until the requirements of serviceability limit state were not met in UHSRRE.Theoretical analysis on the flexural behavior of UHSRRE was conducted.Three kinds of moments at different phases,including cracking moment,yielding moment and ultimate moment,were estimated with three fundamental hypotheses to calculate the flexural capacity.These hypotheses were the constitutive relationships of ECC and ultra high strength rebar,plane section assumption of mean strain,and the tensile stress of ECC in the tensile area of beam.In addition,the requirements of boundary and minimum reinforcement ratio were defined.These theoretical models were verified by the experimental results.