Study on Relation between Concrete''s Surface Carbonization and Stress Erosion
高龄混凝土表面碳化与应力腐蚀关系的研究

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.