酸雨环境下方钢管再生混凝土偏心受压试验研究

Mechanical Study of Recycled Concrete-filled Square Steel Tubes Subjected to Compression-bending under Acid Rain

对酸雨腐蚀后的9根方钢管混凝土进行偏心受压试验研究,主要考虑偏心距、混凝土类型和酸雨腐蚀率变化对试件力学性能的影响。研究表明:整体上酸雨腐蚀试验与法拉第电化学腐蚀定律吻合较好,随着腐蚀率的增加,试件极限承载力、前期刚度及延性均有所降低;混凝土类型对试件破坏形态、极限承载力和前期刚度影响不大,钢管再生混凝土的延性略差于同等条件下的钢管普通混凝土;随着偏心距的增加,试件达到峰值荷载前竖向相对压缩率增大,刚度减小。采用有限元软件对所有试件进行建模分析,整体上有限元建模方法能够较好模拟酸雨环境下方钢管再生混凝土偏心受压全过程,计算所得试件的极限承载力与试验结果较吻合。

Experimental study was conducted on an eccentric compression test of 9 concrete-filled square steel tubes eroded by acid rain.The influence of eccentricity,concrete type and acid rain corrosion rate on the mechanical properties of the specimen was analyzed.The study shows that,the acid rain corrosion experiment on the whole is in good agreement with the Faraday’s law of electrochemical corrosion.With the increase of corrosion degree,the ultimate bearing capacity,the rigidity and ductility of the specimens are all reduced.The type of concrete has little effect on the failure modes,ultimate bearing capacity and rigidity of the specimen.The ductility of the recycled CFST is slightly worse than that of normal CFST under the same conditions.With the increase of the eccentricity,the vertical relative compression ratio increases before the specimens reach the ultimate bearing capacity and the rigidity of specimens decreases.On this basis,finite element method(FEM)was used to model and analyze the specimens.On the whole,the FEM can well simulate the whole process of eccentric compression of recycled CFST under acid rain.The calculated results of FEM are relatively consistent with the experimental results in ultimate bearing capacity.