Exploring the role of extreme thermal conditions and freeze–thaw cycling on crack growth resistance of WMA mixes: an analytical and statistical analysis

Abstract

ABSTRACT Significance of premature failures, such as thermal cracking, on the in-service performance of asphalt pavements, resulted in exploring how cracking resistance of Warm Mix Asphalt (WMA) is affected by its inherent characteristics. Three WMA technologies consisting of the application of organic materials, chemical agents, and foam bitumen technique, coupled with conventional Hot Mix Asphalt (HMA) were used to prepare WMA mixes. Semi-circular bending test was used to investigate cracking potential of the selected WMA mixes. Statistical analysis, comprising of ANOVA, Tukey pairwise, and Spearman’s ranking-order, showed that indices such as WeibullCRI, RDCI, and FI can be adequately used for ranking WMA mixes. Weibull probability distribution function (Weibull PDF) analysis was also applied to determine effects of the testing factors on their failure probability. Results showed that temperature reduction towards −20°C increases probability of fracture failure. Fracture happened more in Sasobit and Foam WMA mixes. However, effects of moisture level and FT cycles on crack evolution was negligible. Finally, failure probability curves of the various WMA mixes were predicted based on the actual probability curves of the control HMA.