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以8根配置500MPa钢筋后张有黏结预应力混凝土梁的弯曲裂缝宽度试验为基础,对不同位置处的裂缝宽度进行统计分析,得到各位置处的短期裂缝宽度扩大系数,比较了不同位置处的裂缝宽度关系;根据试验结果并收集整理相关文献试验数据,建议了不同位置处裂缝宽度换算的计算式。结果表明:各位置处的裂缝宽度均服从正态分布,各位置处的短期裂缝宽度扩大系数基本相同;在梁侧面,预应力筋重心高度处裂缝宽度小于纵向受拉非预应力筋重心高度处裂缝宽度;在梁受拉底面,当裂缝量测点至最近的纵向受拉非预应力筋重心的距离较小时,纵向受拉非预应力筋对量测点处的裂缝具有较好的约束作用;建议计算式可以较好地对不同位置处裂缝宽度进行换算。
Based on the experiment of bending crack width of post-tensioned bonded prestressed concrete beams with 8 bars of 500MPa steel bars, the crack widths at different positions were statistically analyzed to get the expansion coefficient of short-term crack width at each location. According to the test results and collected test data of relevant literature, the formulas for calculating the width of cracks in different locations are proposed. The results show that the crack widths at each location are normal distribution and the short-term crack width expansion coefficients are basically the same at each location. The crack width at the center of gravity of the prestressing tendons is less than the center of gravity of longitudinal tensioned tendons Crack width; longitudinal tensioned non-prestressed tendons have good restraint on the cracks at the measurement point when the distance from the crack measurement point to the nearest longitudinal center of tensile prestress tendon is small ; It is suggested that the formula can better calculate the crack width at different positions.