蠕变断裂试验及初步研究(英文)

混凝土的蠕变断裂试验是一个相当困难的试验,以前还没有人成功地做过这样的试验。我们利用预裂的办法尽量减少混凝土的离散性进行了蠕变断裂试验,获得了蠕变断裂时间和荷载比关系,充分证实了篇变断裂的存在,以及发现在篇变断裂过程中伴随有微裂纹扩展。目前,我们用粘弹性理论蠕变断裂现象进行了初步分析,计算成果和试验非常好地呈现一致性。

PROGRESS REPORT OF CREEP FRACTURE EXPERIMENT FOR CONCRETE

Many of materials have evidently time-dependent response, concrete is one of them. This response has been studied in this paper using the viscoelasticity, especially, creep fracture experiments of plain concrete beams have been done, the creep fracture load ra- tios are 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, respectively. We have obtained the time- dependent curves of each creep fracture deformation and fond that when load ratio is smaller the creeep deformation before failure undergoes jump deformations at regular intervals, when load ratio below some value, may be the fracture will not occur forever becouse load ratios of 0.75, 0.70, 0.65 still are on experiment and are not failure. We have also obtained the relationship curve of load failure. We have also obtained the re- lationship curve of load ratio vs. creep fracture. Then, using the plain FEM, we have calculated the creep fracture time of each load ratio, fracture deep of crack, and analys- ed the mechanism of the crack propagation, these results calculated are agree with the experimental data.