部分预应力叠合受弯构件裂缝计算的新探讨

预制叠合混凝土结构在正常使用极限状态下的裂缝宽度计算方法还没有形成较为成熟的理论。针对这样的现状,从部分预应力叠合受弯构件的特点及其制作过程出发,深入分析了二次受力对叠合断面应力应变状态、断面的初期刚度、裂缝的形成和发展所带来的影响。在参考了各国规范和试验结果的基础上提出了合理的裂缝间距的计算方法,并在此基础上解决了正常使用状态下的裂缝宽度的计算问题。依据建议式得到的诸计算值与实测值完全一致。

Review of Crack Width Calculation for Precast PPC Compsite Members

Precast partially prestressed concrete composite (PCaPPC) member is now widely used in building structures, but so far there is not a reasonable approach to evaluate the cracking of this type of member subjecting to normal service conditions (including ultimate service state). With the consideration of construction process and characteristic of such kind of member, it gives a comprehensive discussion on how secondary loading will affect the section strain distribution, initial stiffness of section, the formation of cracks and their propagation. Based on experimental study and the reference of the Codes of China, Europe and Japan, a reasonable method of crack width calculation is recommended for partially pre-stressed composite member. At last, the calculated values with the use of recommended method are compared with those from experimental measurements, and resulted in good agreement.