Flexural-fatigue characteristics of pervious concrete: Statistical distributions and model development

Pervious concrete pavements that are widely used as surface layers in low volume road applications such as parking lots, residential streets, etc. are subjected to repeated loads, which may undergo fatigue. Although most of the past studies have focused on the compressive strength and hydraulic properties, limited investigations have been reported in respect of fatigue in pervious concrete (PC). The objective of this study was to investigate the effect of stress levels and frequencies on the fatigue life and develop laboratory fatigue models of PC mixtures. The S-N curves indicated that power-function relation exists between stress levels and fatigue life of PC. The non-parametric and parametric methods indicated that the stress levels (0.70, 0.75, and 0.80) and stiffness were significant in affecting the fatigue life compared to the loading frequency in the range of 2-10 Hz. The fatigue relations of PC fitted with 3-Parameter Weibull and lognormal distributions indicated the characteristic infant mortality type of failure behavior, represented by initial portion of the reliability bathtub curve. The stiffness degradation and tensile strain accumulation depicted a three-stage process with rapid degradation in the primary stage, stable and constant degradation in secondary phase, and accelerated degradation in the tertiary stage. The laboratory fatigue models developed had good-to-fair statistical goodness of fit parameters (0.65 ≤ R2 ≤ 0.85), which can be used to predict the fatigue lives of pervious concrete in case of non-availability of testing capabilities.