The concrete specimens with diameter of 300mm,height of 600mm, were preprocessed under 0 cycle,10 cycles,50 cycles,100 cycles,200 cycles of pore water pressure(upper limit of pore water pressure for 3MPa,the lower limit for 1MPa) .In order to study mechanical properties of concrete under different cycles of pore water pressures and different strain rates, we carried out conventional triaxial(σ2=σ3≥σ1) compressive tests for these specimens under four strain rates(10-5/s,10-4/s,10-3/s,10-2/s)with confining pressure of 3 MPa. The results show that 1) with the increasing strain rate,the peak stress of concrete increases and the peak strain shows increasing trend. 2) Before 100 cycles of pore water pressure,the peak stress gradually increase, but after that the peak stress tends to decrease, so the peak stress of concrete changes by phase with the increasing cycles of pore water pressure. Variation of peak strain is irregular, whereas elastic modulus tends to decrease with the increasing cycles of pore water pressure.
Key words
concrete /
cyclic pore water pressure /
peak stress /
strain rate /
elastic modulus
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References
[1] BUTLER J E. The Influence of Pore Pressure upon Concrete[J]. Magazine of Concrete Research,1981,33(114):3-17.
[2] ROSSI P. Influence of Cracking in the Presence of Free Water on the Mechanical Behavior of Concrete[J]. Magazine of Concrete Research,1991,43:53-57.
[3] OSHITA H,TANA B E. Modeling of Water Migration Phenomenon in Concrete as Homogeneous Material[J]. Journal of Engineering Mechanics,2000,126(6):565-572.
[4] YAMAN I O,HEARN N,AKTAN H M. Active and Non-active Porosity in Concrete Part Ⅰ: Experimental Evidence[J]. Materials and Structures,2002,35:102-109.
[5] YAMAN I O,AKTAN H M,HEARN N. Active and Non-active Porosity in Concrete Part Ⅱ: Evaluation of Existing Models[J]. Materials and Structures,2002,35:110-116
[6] 闫东明,林 皋,王 哲,等. 不同环境下混凝土动态直接拉伸特性研究[J]. 大连理工大学学报,2005,45(3):416-421.
[7] 王海龙,李庆斌. 孔隙水对湿态混凝土抗压强度的影响[J]. 工程力学,2006,23(10):141-144.
[8] 黄桥平. 基于Stefan效应的混凝土随机细观黏性损伤模型[J]. 结构工程师,2013,29(4):31-37.