DETERIORATION MECHANISM OF REINFORCED CONCRETE COLUMNS SUFFERED CORROSION AND FREEZE-THAW CYCLES

摘要

Reinforced concrete structures in coastal regions are usually subjected to seawater corrosion and freeze-thaw cycles,as well as sustained loading during service.The comprehensive effects would degrade the structure mechanics significantly.Eexperiments are conducted on reinforced concrete eccentric loading columns subjected to sustained loading,comparing with columns subjected to seawater corrosion and freeze-thaw cycles as well as sustained loading,and then the deterioration mechanism is discussed in the paper.The experimental results show that compared to the columns immersed in water,the mechanical properties of columns are decreased after the alternative action of freeze-thaw cycles and immersed in seawater.After freeze-thaw cycles,the inner cracks in concrete are developed and deepened.And the material mechanical properties are degraded due to physical and chemical action especially when subjected to alternative action of freeze-thaw and seawater corrosion.The sustained loading accelerates the development of inner cracks as well as concrete degradation and steel rust,which leads to the mechanical degradation of reinforced concrete columns.The mechanics performance of reinforced concrete columns subjected to sustained loading are decreased most significantly after the alternate action of freeze-thaw cycles and seawater corrosion.