Analysis of fatigue and cumulative damage characteristics for concrete in freezing-thawing environment

Through analyzing the characteristic of concrete freezing-thawing cumulative damage, concrete freezing-thawing damage can be with fatigue problems with similar methods to analysis. Coagulation Earth material property discrete and cause damage in a given amount of state natural freeze-thaw cycle times is a random variable, analysis found that it is better to obey three- parameter Weibull distribution. Based on three parameters Weibull distribution model, the test data in had established, on the basis of freezing-thawing environment concrete damage and freeze-thaw cycles of the probability of the relation curve, and regression to obtain different guarantee rate of freezing-thawing damage cumulative model for freezing-thawing environment,which could be provides reference for concrete service life prediction and health diagnosis. At present, reinforced concrete is the most prevalent construction material used in building structure Freezing-thawing cycle can be caused destruction of concrete are generally exhibit surface of osteoporosis, spalling, aggregate exposure, and even exposed steel bar etc. The concrete buildings in the cold area, especially those in the alternating wet and dry environment structure, such as dams, bridge, culvert, port engineering, often due to alternation of freezing-thawing cycles occur durability damage, can not meet the design service life. The concrete building in the environment of alternating positive and negative temperaturea, and internal containing more water, will occur freezing-thawing damage, so the freezng- thawing damage is the most representative indicator of concrete durability([1]). In this paper, based on the existing experiment data and three parameters of the Weibull distribution model, established the curves of concrete in freezing-thawing circumstance are defined to describe probabilistic relationships between damage and freezing-thawing cycle number. It can quantitative analysis the concrete damage and the freezing-thawing cycle number in freezing-thawing environment, study of concrete fatigue and damage accumulation rule in freezing-thawing environment, for concrete health diagnosis and life prediction offer reference and basis.