部分预应力混凝土受弯构件裂缝宽度计算方法探讨

Discussion on the method for calculating crack width of partial prestressed concrete beams

对于部分预应力混凝土受弯构件在使用阶段的抗裂问题,《混凝土结构设计规范》给出了相应的裂缝宽度计算公式,但此公式较为复杂,尤其是消压后钢筋应力增量的计算。用名义拉应力法进行裂缝控制简单方便,但往往不能直接用于裂缝宽度计算或精度较差。以规范裂缝宽度计算思路为基础,加以修改,引入名义拉应力,建立以名义拉应力表示的裂缝宽度计算公式,大大简化计算,且具有较高的精度。

Code for design of concrete structures of China presents the expression for calculating crack width of partial prestressed concrete beams. But the expression is quite complicated. Nominal tensile stress method for prestressed concrete crack control is very simple, but it can not be used to calculate crack width. Based on the method of code, we made some modifications and got a expression with nominal tensile stress for calculating crack width of partial prestressed concrete beams. The proposed expression is more simple and has satisfied precision.