Investigation of fatigue cracks on RAP mixtures containing Sasobit and crumb rubber based on fracture energy

• Published in: Construction & building materials Vol. 141; pp. 526 - 532
• Main Authors: Behroozikhah, Abdolhamid, Morafa, Seyed Hasan, Aflaki, Sassan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.06.2017; Elsevier B.V
• Subjects: Dissipated Creep Strain Energy (DCSE); Energy Ratio (ER); Fatigue (Materials); Fatigue cracking; Fracture Energy (FE); Indirect Tensile Strength; Investigations; Resilient Modulus; Rubber; Rubber products; Iran; Fracture Energy (FE); Resilient Modulus; Dissipated Creep Strain Energy (DCSE); Energy Ratio (ER); Indirect Tensile Strength; Fatigue cracking
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.03.011

•Prepared samples indicate greater Resilient Modulus than virgin sample.•Generally, creep compliance and m-value reduce by adding of RAP, crumb rubber and Sasobit.•Tensile strength of mixtures increases by adding of RAP and crumb rubber.•Crack initiation threshold reduces but fracture energy and fatigue resistance increase by adding of studied additives.•Sample containing 30% of RAP, 20% of crumb rubber and no Sasobit has the greatest fatigue resistance. Fatigue cracking, rutting and low temperature cracking are three major distresses of asphalt mixtures. In last years, different methods based on fracture mechanic have been developed to measure performance of asphalt mixtures due to cracking. In this study, fracture mechanic method developed by Roque et al. has been employed to evaluate fatigue cracking performance of modified asphalt mixtures. Samples containing Reclaimed Asphalt Pavement (RAP) with different percentages of Sasobit (as a Warm Mix Asphalt additive) and crumb rubber were built. Resilient Modulus, static creep and Indirect Tensile (IDT) tests also conducted on samples and Resilient Modulus, creep compliance and Indirect Tensile Strength were measured. Based on fracture mechanic, Dissipated Creep Strain Energy (DCSE) was calculated for each sample, and fatigue strength of mixtures were investigated. The results indicated that the use of RAP, crumb rubber and Sasobit simultaneously caused desirable fatigue performance of modified mixtures. These mixtures had better Resilient Modulus and more loading capacity, as well as, lower cumulative damage rates rather than virgin sample. The ITS results also indicated more appreciable improvement in crack initiation threshold, Fracture Energy (FE) and Energy Ratio (ER).