Phoeuk Menghay, Choi Dong-Yeong, Kwon Minho
Department of Civil Engineering, Gyeongsang National University, Jinju 52828, Republic of Korea.
Materials (Basel). 2024 Dec 25;18(1):35. doi: 10.3390/ma18010035.
Corrosion in reinforced concrete (RC) structures has led to the increased adoption of non-corrosive materials, such as carbon fiber-reinforced polymers (CFRPs), as replacements for traditional steel rebar. However, ensuring the long-term reliability of CFRP grids under sustained stress is critical for achieving safe and effective designs. This study investigates the long-term tensile creep rupture behavior of CFRP grids to establish a design threshold for their tensile strength under sustained loading conditions in demanding structural applications. A comprehensive laboratory experiment was conducted over 10,000 h, during which CFRP grid specimens were subjected to constant stress levels ranging from 92% to 98% of their ultimate tensile strength. The results confirm the excellent creep rupture resistance of CFRP grids. Specimens subjected to a sustained stress ratio of 92% of their ultimate tensile strength remained intact throughout the testing period, with minimal creep strain ranging from approximately 1% to 4% of the initial strain. The mean extrapolated creep rupture factors were found to be 92.1% and 91.7% of their ultimate tensile strength for service lives of 50 and 114 years, respectively. Based on the results of this study, a tensile stress limit of 48% of the ultimate tensile strength is recommended for CFRP grids to ensure long-term creep rupture resistance over a 100-year service life.
钢筋混凝土（RC）结构中的腐蚀现象促使人们更多地采用非腐蚀性材料，如碳纤维增强聚合物（CFRP），来替代传统的钢筋。然而，在持续应力作用下确保CFRP网格的长期可靠性对于实现安全有效的设计至关重要。本研究调查了CFRP网格的长期拉伸蠕变断裂行为，以确定在苛刻结构应用中持续加载条件下其拉伸强度的设计阈值。进行了一项为期10000小时的全面实验室试验，在此期间，CFRP网格试件承受的恒定应力水平为其极限抗拉强度的92%至98%。结果证实了CFRP网格具有出色的抗蠕变断裂性能。承受极限抗拉强度92%持续应力比的试件在整个测试期间保持完好，最小蠕变应变范围约为初始应变的1%至4%。对于50年和114年的使用寿命，平均外推蠕变断裂系数分别为其极限抗拉强度的92.1%和91.7%。基于本研究结果，建议CFRP网格的拉应力极限为极限抗拉强度的48%，以确保在100年使用寿命内具有长期抗蠕变断裂性能。
