College of Architectural Engineering, Dalian University, Dalian, China.
Architecture and Civil Engineering Institute, Guangdong University of Petrochemical Technology, Maoming, China.
PLoS One. 2023 Feb 6;18(2):e0276280. doi: 10.1371/journal.pone.0276280. eCollection 2023.
Ocean crossing bridges suffer from seawater corrosion all year round and their mechanical properties will be substantially diminished. In order to enhance the mechanical properties of reinforced concrete columns corroded by seawater, SMA wire is used to restrain the reinforced concrete columns corroded by seawater to study their mechanical properties. 14 specimens were produced through the test, and the natural seawater corrosion was simulated by preparing a certain concentration of synthetic seawater. The mechanical properties of SMA strengthened specimens and unreinforced specimens are compared and analyzed, including failure mode, hysteresis curve, bearing capacity, ductility, stiffness and energy dissipation; the effects of different synthetic seawater corrosion concentrations on the mechanical properties of reinforced concrete columns are discussed. The results show that the bearing capacity and stiffness of reinforced concrete columns subjected to synthetic seawater corrosion are substantially diminished than those of uncorroded specimens, and the bearing capacity of specimens decreases more with the increase of synthetic seawater corrosion concentration; synthetic seawater corrosion has obscure effect on the ductility and energy dissipation performance of the specimens. The mechanical properties of the corroded specimens strengthened with SMA wire have been substantially enhanced, particularly the energy dissipation performance and bearing capacity have been notably enhanced, and the ductility and stiffness have also been somewhat enhanced. At the same time, based on the test, the finite element model is created according to the test specimen, while the accuracy of the model is verified, and the effects of the spacing and diameter of SMA wire, the strength of concrete and the thickness of protective layer on the mechanical properties of the specimen are analyzed.
跨海桥梁常年遭受海水腐蚀，其力学性能会大幅降低。为了提高受海水腐蚀的钢筋混凝土柱的力学性能，采用 SMA 钢丝对受海水腐蚀的钢筋混凝土柱进行约束，研究其力学性能。通过试验制作了 14 个试件，采用配制一定浓度的人工海水模拟自然海水腐蚀。对比分析了 SMA 加固试件和未加固试件的破坏形态、滞回曲线、承载力、延性、刚度和耗能等力学性能，讨论了不同人工海水腐蚀浓度对钢筋混凝土柱力学性能的影响。结果表明，受人工海水腐蚀后钢筋混凝土柱的承载力和刚度均大幅降低，且试件承载力随人工海水腐蚀浓度的增加而降低幅度增大；人工海水腐蚀对试件的延性和耗能性能影响不明显。SMA 钢丝加固后的腐蚀试件力学性能得到了显著提高，尤其是耗能性能和承载力得到了明显提高，延性和刚度也有所提高。同时，基于试验，根据试验试件建立了有限元模型，并对模型的准确性进行了验证，分析了 SMA 钢丝的间距和直径、混凝土强度和保护层厚度对试件力学性能的影响。
