疲劳-冻融多次交互作用下混凝土损伤特性试验研究

摘要

通过对混凝土棱柱体试件进行疲劳荷载和冻融循环交互试验,分析疲劳荷载及冻融循环次数对试验后试件外观形貌、质量、相对动弹性模量和抗压强度的损伤劣化影响.试验结果表明:随着交互试验次数的增多,混凝土试件表面的坑洼面变多、孔洞变大,粗细骨料分离,质量出现先增加后减小的变化趋势,相对动弹性模量及试件的抗压强度下降速率明显加快.3个试验周期后,交互作用的试件与仅冻融循环的试件相比,试件的质量损失率增加0.36%,相对动弹性模量下降30.6%.混凝土的抗压强度降低18.1%.%The interaction experiments are conducted on the concrete specimens with the fatigue loading and freeze-thaw cycles.The influence of multiple interaction on specimens was investigated through the appearance and the changes in mass,relative dynamic elastic modulus and compressive strength of the specimens experienced damage history.The results show that there are more potholes and bigger holes on the surface of the specimens and the coarse aggregate and fine aggregate are separated with the increasing of interaction times.The mass first increases and then decreases.The relative dynamic elastic modulus and the compressive strength decrease obviously.Results compared with the specimens exposed to freeze-thaw cycles alone,the mass loss rate of specimen increases by 0.36%,the relative dynamic elastic modulus of specimen decreases by 30.6% and the compressive strength of specimen decreases by 18.1% after the three interaction of fatigue and freezing-thawing cycles.