Reliability assessment on maximum crack width of concrete beams reinforced with high-strength steel bars
Reliability assessment on maximum crack width of concrete beams reinforced with high-strength steel bars
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DOI：
10.1016/j.jobe.2021.103564
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发表时间：
2022-01
影响因子：
6.4
通讯作者：
Xiaoxu Huang;Yiqi Bei;L. Sui;Long-yuan Li;Biao Hu;Yingwu Zhou
中科院分区：
文献类型：
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作者：
Xiaoxu Huang;Yiqi Bei;L. Sui;Long-yuan Li;Biao Hu;Yingwu Zhou
在荷载和时间的作用下，钢筋混凝土结构不可避免地会产生裂缝，从而导致钢筋混凝土结构的美观性、长期耐久性乃至结构安全性等问题。尽管高强钢筋带来了可观的经济效益，但与低强度钢筋相比，高强钢筋的应用导致了钢筋混凝土构件更大的裂缝宽度。因此，对高强钢筋混凝土构件最大裂缝宽度的安全水平进行量化是十分必要的。本文建立了包含1309组裂缝宽度数据的实验数据库，并从模型误差的角度对裂缝宽度预测模型进行了评价。在此基础上，对6种常用混凝土设计规范中的高强钢筋混凝土梁和低强度钢筋混凝土梁的最大裂缝宽度正常使用极限状态（SLS）进行了系统的可靠度评估。结果表明，与低强度钢筋相比，高强度钢筋配置的SLS最大裂缝宽度的可靠指标较低。此外，进行了参数研究，以确定最大裂缝宽度的可靠性水平的影响。在此基础上，提出了以可靠度为目标控制混凝土构件最大裂缝宽度的优化设计方法。与低强度钢筋相比，在承载力和裂缝宽度安全水平相当的情况下，高强钢筋所需配筋率相对较小，说明通过合理设计，高强钢筋的经济优势可以充分体现出来。
Under the effect of load and time, cracks occur inevitability, leading to the issues of aesthetics, long-term durability, and even structural safety for reinforced concrete (RC) structures. Despite a promising economic benefit brought by high-strength steel bars, the application leads to a wider crack width for RC members compared with low-strength ones. Therefore, the quantification of the safety level on maximum crack width for RC members with high-strength steel bars is essential. In this paper, an experimental database that contains 1309 sets of data for crack width was constructed, and the prediction models of crack width were assessed in terms of model error. Then, the reliability assessment for serviceability limit state (SLS) of maximum crack width was performed systematically for RC beams with high-strength steel bars and low-strength ones within six well-recognized concrete design guidelines. The results showed that the reliability index for SLS of maximum crack width was lower for high-strength reinforcement configuration compared with low-strength ones. Furthermore, a parametric study was conducted to identify the effect on the reliability level of the maximum crack width. Subsequently, an optimum design procedure was given to control the maximum crack width for concrete members in terms of reliability level. Compared with low-strength steel bars, the required steel ratio was relatively small for high-strength ones with equivalent bearing capacity and safety level of crack width, indicating that the economic advantages of high-strength steel bars can be shown sufficiently by reasonable design.