Effects of aggregate shape and size and surfactants on the resilient modulus of bituminous mixes

The resilient modulus of bituminous mixes is a fundamental property to bear in mind in pavement design as it enables the estimation of their structural behavior in roads. In this work, a comparative study of some fundamental variables has been carried out to determine their effect on the resilient modulus obtained using the indirect tensile test on cylindrical samples. To this end, the variables studied were gradation, aggregate type and origin, whether crushed or rounded, binder penetration, surfactants use and manufacture and compaction temperature. From the results obtained it can be concluded that the variables that most affect the modulus were bitumen penetration and manufacture and compaction temperature. These results were verified through statistical analysis, to this end an analysis of variance was performed and regressions models, with high coefficients of determination, were obtained. The statistical results clearly validate the concept of using the bitumen penetration and the temperature to estimate the resilient modulus.