School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330013, China.
Sensors (Basel). 2018 Dec 2;18(12):4231. doi: 10.3390/s18124231.
Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear⁻elastic property of FRP reinforcement. Hybrid steel-FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel-FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel-FRP-reinforced concrete-engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel-FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially.
纤维增强聚合物（FRP）由于其耐腐蚀、重量轻、无磁性和高强度的特性，在混凝土结构中得到了广泛的应用。然而，由于 FRP 增强材料的线弹性性质，FRP 增强混凝土受弯构件表现出低延性。由于钢加固的弹塑性变形，混合钢-FRP 增强混凝土受弯构件在弯曲下表现出良好的强度和延性。由于 FRP 棒材的抗压性能较差，现有研究主要集中在混合钢-FRP 增强受弯构件的力学性能上。只有少数研究报道了在组合弯曲和压缩荷载下的构件，如柱，这是由于 FRP 棒材的抗压性能较差。本文提出了一种新型混合钢-FRP 增强混凝土-工程水泥基复合材料（ECC）组合柱，在塑性铰区采用 ECC，并对其进行了反复循环加载试验。还对混合钢-FRP 增强混凝土柱进行了测试作为比较。系统评估了塑性铰区基体类型对柱的破坏模式、裂缝模式、极限强度、延性和耗能能力的影响。我们发现，用 ECC 代替塑性铰区的混凝土可以有效地防止 FRP 棒的局部屈曲，从而显著提高柱的强度和延性。
