预应力高强混凝土梁抗裂度和裂缝宽度试验研究

Experimental Study on Cracking Width and Strength of Prestressed High-strength Concrete Beams

概括介绍了预应力比率为 0 6～ 1 0、混凝土强度等级为C40～C80的 1 4根先张法预应力高强混凝土梁的抗裂度和裂缝宽度的试验结果。通过与《混凝土结构设计规范》(GB5 0 0 1 0— 2 0 0 2 )相关计算公式进行对比分析 ,讨论了混凝土强度对截面抵抗矩塑性系数的影响作用 ,提出了修正系数计算公式 ;分析了混凝土强度、预应力比率对受拉钢筋的等效应力、平均裂缝间距及裂缝宽度的影响规律 ,给出了规范裂缝宽度计算公式的预应力比率适用范围 。

The test results of cracking strength and crack width on fourteen prestressed high strength concrete beams with the prestressing ratio from 0 6 to 1 0 and the concrete strength grade from C40 to C80 are introduced. Based on the comparative analysis to the calculation results of formulas specified in design code GB50010—2002, the effect of concrete strength on the plasticity coefficient of cracking sectional resistance moment is discussed, the revised coefficient formula is proposed. The effects of the concrete strength, the prestressing ratio on the stress of tensile reinforcement, the crack spacing and the crack width are analyzed. The prestressing ratio range suited to calculate the crack width of the formulas is suggested for design code GB50010—2002, and the revised method is proposed.