Development of Resilient Modulus Model for the Bituminous Course

As per IRC 37, the design of flexible pavement requires the accurate prediction of resilient modulus for bituminous concrete. This, determination of \({\mathrm{M}}_{\mathrm{r}}\) requires specialized test equipment, which may not be available in many laboratories. Therefore, it would be rather reasonable to create a model that could estimate \({\mathrm{M}}_{\mathrm{r}}\) from easy to estimate volumetric parameters and other parameters obtained from sample conventional tests. This study aims to investigate the effect of different binders (VG30, VG40, PMB and CRMB), binder contents, volumetric parameters (air voids) and temperature on Resilient Modulus ( \({\mathrm{M}}_{\mathrm{r}}\) ) in Bituminous Concrete (BC) course and Dense Bituminous Macadam (DBM) course. The samples were compacted using the Marshall Compacter and subsequently the volumetric parameters were calculated. The Indirect Tensile Strength (ITS) test was conducted to calculate the ITS and Toughness. The Repeated Load Indirect Tension Test was conducted to find out the Resilient modulus ( \({\mathrm{M}}_{\mathrm{r}}\) ) values for all mixes. The regression analysis was performed using the Microsoft Excel tool, and the relationship between resilient modulus, volumetric parameters and ITS was developed. Using the final model, Resilient Modulus of mixtures may be predicted from volumetric parameters and indirect tensile strength under comparable or different testing conditions.