Effect of seawater wet-dry cycles on mechanical performance of RC beams with initial damage
PANG Sen1,2, DIAO Bo1,2, YE Yinghua1, WANG Xin1, CHEN Shuxin1
1. School of Transportation Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China;
2. State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640, China
Abstract：The working condition of reinforced concrete (RC) structures in coastal chloride environment combined load effects and environmental effects and there would be a different degree of damage due to load effects in normal conditions. In order to simulated that working condition in laboratory, different loads of 0.3Pu, 0.4Pu, 0.5Pu, 0.6Pu and 0.7Pu (Pu is the ultimate load of beam under monotonic loading) were applied on RC beam specimens to induce varying degrees of damage. Subsequently, beam specimens were placed in an automatic sprinkler device to simulate seawater wet-dry cycles. After 120 wet-dry cycles, monotonic loading test and chloride concentration test were conducted on RC beams. The test results show that the yield load, ultimate load and ductility of specimens decrease with the increase of initial damage load amplitude. When the initial load is 0.4Pu, the decrease of yield load and ultimate load is 10.4% and 7.9% respectively, compared with control group. With the damage increasing, the yield load and ultimate load decrease constantly. When the initial load is 0.7Pu, a great degeneration of mechanical performance occurs and the decrease of yield load and ultimate load is 33.7% and 32.4% respectively. The results of chloride concentration test show that the chloride ion content of concrete in tension area is higher than that in compression area. When the initial load is below 0.5Pu, the chloride ion content in steel position is below 0.1% and has no significant changes. When the initial load is 0.7Pu, the chloride ion content increases significantly and the maximum value is up to 0.14%. Thus, the initial damage combined with seawater wet-dry cycles has a great impact on degradation of mechanical performance and durability of RC beams.
庞森, 刁波, 叶英华, 王鑫, 陈树鑫. 海水干湿循环对初始损伤RC梁力学性能的影响[J]. 北京航空航天大学学报, 2017, 43(5): 1004-1012.
PANG Sen, DIAO Bo, YE Yinghua, WANG Xin, CHEN Shuxin. Effect of seawater wet-dry cycles on mechanical performance of RC beams with initial damage. JOURNAL OF BEIJING UNIVERSITY OF AERONAUTICS AND A, 2017, 43(5): 1004-1012.
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2017, Vol. 43 
