Experimental Study On Seismic Performance Of Reinforced Concrete Column After Freezing And Thawing

The concrete structures located in the cold region usually are destroyed because offreezing and thawing, and frost resistance is an important aspect of durability ofconcrete structure. At present, the research on concrete structures’ seismic performanceafter freezing and thawing is little at home and abroad.In order to obtain better understanding of concrete structures’ seismicperformance after freezing and thawing, and provide reliable scientific experimentaldata for anti-freeze concrete structures’ design and construction standards orspecifications. The present paper is proposed to study on seismic performance ofreinforced concrete columns after freezing and thawing, sponsored by excrementalresearch on seismic performance evaluations and nonlinear dynamical behavior ofexisting concrete structure under the freeze-thaw cycles and corrosion (grant number:51078307)of National Natural Science Foundation of China:1. Firstly four batch of8size of200mm×200mm×1180mm concrete columns wereexposed to freeze-thaw cycles,which involving0times、100times、200times and300times. And then,8columns after freezing and thawing subjected to low cyclic reversedlateral loads.2. Comparing the mechanical properties of concrete long columns after freezingand thawing and the common concrete long columns under low cyclic reversed loadingby experimentation, relationship between the changing of hysteretic curves obtainedfrom the test results and the freeze-thaw cycles is analyzed. And the influences offreezing and thawing on concrete columns’ seismic performance are discussed.3. Comparing the axial compression ratio’ influence to the ductility of concrete long columns after freezing and thawing and the common concrete long columns, theinfluences of different axial compression ratios on concrete columns’ seismicperformance are discussed.The research shows that the influence of number of cyclic freezing and thawingand axial compression ratio on seismic performance of concrete columns is significant.With the increasing of the cyclic number the seismic performance of concrete columnsdecline rapidly; after the same number of cyclic freezing and thawing, concrete columnwith different axial compression ratios has different mechanical properties. With theincreasing of axial compression ratios the energy-dissipating capacity, the ductility, theseismic performance of concrete columns decline rapidly.