无粘结预应力混凝土梁裂缝控制设计方法研究

Calculation of crack widths in unbonded partially prestressed concrete members

研究了无粘结预应力混凝土梁的裂缝控制设计方法,利用将无粘结预应力筋的拉力作为构件截面外力的思路,把无粘结预应力混凝土梁的裂缝宽度计算,转化为普通钢筋混凝土梁的裂缝宽度计算,提出了与GB50010-2002《混凝土结构设计规范》相衔接的无粘结预应力混凝土梁的裂缝宽度计算公式及裂缝宽度限值.与已收集到的84组无粘结预应力混凝土梁模型试验的裂缝宽度实测值相比较,验证了本文建议的无粘结预应力混凝土梁的裂缝宽度计算公式的合理性,可供我国今后修订相关规范时参考.

The calculation of crack width in unbonded partially prestressed concrete beams in Chinese code is studied.Based on the idea which takes the unbonded reinforcement tension as external forces,the calculation of crack width in unbonded partially prestressed concrete members is converted to the one in bonded partially prestressed concrete members.A new formula which can be combined with bonded partially prestressed beams in GB50010-2002 is proposed.84 model test results of crack widths in unbonded partially prestressed concrete members in two different references indicate that the new formula is reasonable,so as to make some reference for code revising in crack control.