Building Materials Durability: Semi‐Markov Approach

A systematic approach to the study of durability of building materials is attempted with reference to porous materials in an aggressive environment. The service lives of these materials strongly depend on the environmental conditions that cause chemical, physical, and mechanical degradation. A service life prediction can be made only when data can be collected on material properties, environmental conditions, and their influence on property variations in time. When inservice data are very poor, measurement of the deterioration as a function of time can be obtained by laboratory aging tests. A crystallization test based on wet‐dry cycles is performed to study the behavior of solid bricks. The experimental decay process is examined both for new and repaired materials. From the mathematical point of view a semi‐Markov model is applied to interpret the experimental results. The results depend on the probability distributions within the model; distributions that are a mixture of two Weibull distributions seem to be a suitable choice to represent the service lifetime behavior.