摘要
对多栋在役80年的混凝土建筑进行调查,检测了不同受力状态下的高龄混凝土构件的表面回弹值,并设计了一组混凝土构件老化室内模拟实验,用以分析高龄混凝土结构表面碳化发展机理。研究结果表明:普通混凝土的表面碳化速度与结构应力状态密切关联,处于拉应力状态的区域,其碳化深度明显大于压应力或无应力区域,表面碳化成为微观裂纹形成的基础,而微观裂纹的扩展将导致钢筋的锈蚀,最终导致结构承载力下降。只有处于低应力状态的混凝土才有可能达到理想的在役年限。该结论对于正确评估混凝土结构的寿命提供了实验依据。
The paper surveys a great deal of old concrete buildings which were built eighty years ago, measures the rebound value of old concrete components that bear differ stress,and designs a simulated experiment on aging concrete components, in order to analyze the cause of surface carbonization of old concrete. Result indicates that surface carbonization rate of common concrete is significantly attributed to the structure stress. The carbonization depth of pull stress area is more remarkable than that under press stress zone or no stress realm. The surface carbonization causes small cracks. The spread of those small cracks leads to the rusting of reinforcing bar. Consequently, the ability of component to bear the weight drops. In conclusion, only the concrete in low stress can survive to the service life of the concrete. The result can be used to evaluate the life-span of concretes.
出处
《实验力学》
CSCD
北大核心
2007年第5期495-499,共5页
Journal of Experimental Mechanics
关键词
高龄混凝土
表面碳化
应力腐蚀
old concrete
surface carbonization
stress erosion
