Fatigue Analysis of High Performance Cement Concrete for Pavements using the Probabilistic Approach

Cement concrete pavements are designed for flexural fatigue loading due to traffic. Due to its numerous advantages high performance cement concrete is finding it’s way in pavement construction. This paper investigates the fatigue strength of High Performance Cement Concretes subjected to flexural loading. Fatigue studies are conducted on these concretes to obtain the fatigue lives at various stress levels. Static flexural strength tests are conducted to determine the static failure loads on prism specimen. From the experimental studies carried out, the number of load repetitions to failure on the concretes under study is determined for three stress ratios. From the data obtained S-N curves are developed using linear regression models considering log normal distribution as is being presently adopted. Recent literature shows that weibull distribution is found to have more convincing physical features than the lognormal distribution to describe the fatigue behavior of concrete. To incorporate the probability of failure, weibull distribution is considered and Pf-S-N diagram are developed. It is observed that addition of fly ash and silica fume improves the fatigue performance of concrete by48% and 83% at a stress level of 0.75. Keywords— Fatigue, Flexure, High Performance Cement Concrete, Rigid Pavement, Statistical Distributions