预应力碳纤维布加固混凝土梁截面应力及抗弯刚度

碳纤维布施加预应力后粘贴加固可有效改善混凝土梁正常使用阶段的工作性能,相应截面应力和抗弯刚度分析对于合理评价加固梁的工作状态有重要意义。根据预应力碳纤维布加固混凝土梁正常使用阶段的截面受力分析,提出了截面应力的简化计算方法,进而通过引入碳纤维布应变不均匀系数,得出了对于未加固梁、非预应力碳纤维布加固梁和预应力碳纤维布加固梁均适用的截面短期抗弯刚度的实用计算方法。试验结果对比表明,建议的截面应力和抗弯刚度计算方法准确度较高。

Analysis on Stress and Short-term Flexural Stiffness of Strengthened RC Beam Prestressed with CFRP Sheets

The behavior of RC beams strengthened with prestressed CFRP sheets under service loading can be improved effectively.The stress and short-term stiffness of the Strengthened RC Beam Prestressed with CFRP Sheets have attracted more and more attention.A method to determine section stress of strengthened beam with prestressed CFRP sheets under service loading is put forward,furthermore,by introducing coefficient of non-uniformity of longitudinal CFRP strain between cracks,the short-term flexural stiffness of strengthened beam is also studied and a unified model suitable for RC beams and strengthened RC beams with pretressed and non-pretressed CFRP sheets is proposed.The calculated results of suggested method are compared and shown to agree well with the test results.