Gao Jing, Xu Penghai, Fan Lingyun, Terrasi Giovanni Pietro
Department of Civil Engineering, Xiamen University, Daxue Road 182, Xiamen 361005, China.
Mechanical Systems Engineering Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
Polymers (Basel). 2022 Jun 30;14(13):2689. doi: 10.3390/polym14132689.
The application of CFRP bar and seawater sea-sand concrete (SSSC) in construction can overcome the shortcomings in conventional reinforced concrete, such as corrosion induced by carbonation and chloride ingress. In this study, the bond-slip behavior between an SSSC cube and CFRP bar has been investigated, and different CFRP bar surface shapes have been considered. A total of 27 specimens (9 groups) were fabricated for a pull-out test, where three types of CFRP bar with different surface shapes were used: smooth regular bars, double-wrapped bars and ribbed bars. Bond strength, bond-slip curve, and failure mode have been presented and discussed. FE models have been constructed and validated by experimental results. The effect of concrete compressive strength and relative area of ribs on bond strength has been studied through numerical simulations. It is found that the bond strength increased with concrete compressive strength, and the ribbed bar had significantly higher bond strength than the smooth regular bar. Pull-out failure was observed when the cover-depth-to-bar-diameter ratio was no less than 4 and, otherwise, splitting failure occurred. In addition, a simple formula has been proposed to approximately evaluate the bond strength between an SSSC cube and CFRP bar and validated by experimental results, and analytical expressions for different bond-slip curves have also been developed.
碳纤维增强塑料（CFRP）筋与海水海砂混凝土（SSSC）在建筑中的应用能够克服传统钢筋混凝土存在的诸如碳化和氯化物侵入导致腐蚀等缺点。在本研究中，对SSSC立方体与CFRP筋之间的粘结-滑移行为进行了研究，并考虑了不同的CFRP筋表面形状。总共制作了27个试件（9组）用于拉拔试验，试验中使用了三种具有不同表面形状的CFRP筋：光滑直筋、双包裹筋和带肋筋。给出并讨论了粘结强度、粘结-滑移曲线和破坏模式。构建了有限元模型并通过试验结果进行了验证。通过数值模拟研究了混凝土抗压强度和肋的相对面积对粘结强度的影响。研究发现，粘结强度随混凝土抗压强度的增加而提高，带肋筋的粘结强度明显高于光滑直筋。当保护层厚度与钢筋直径之比不小于4时，观察到拉拔破坏，否则发生劈裂破坏。此外，提出了一个简单公式来近似评估SSSC立方体与CFRP筋之间的粘结强度，并通过试验结果进行了验证，还推导了不同粘结-滑移曲线的解析表达式。
