Evaluation of high modulus mixture behaviour with high reclaimed asphalt pavement (RAP) percentages for sustainable road construction

The aim of this work is to characterize the behaviour of high modulus bituminous mixes with low penetration grade bitumen and high reclaimed asphalt pavement (RAP) percentages. Four mixtures with RAP percentages of 0%, 15%, 30% and 50%, respectively, were analyzed. Their volumetric and mechanical characteristics were evaluated for several binder contents to define a job mix formula for real scale testing. Mechanical properties included stiffness modulus, toughness, moisture sensitivity, resistance to rutting and fatigue resistance. The most important conclusion is that it is possible to prepare high modulus mixtures (HMM) with high RAP contents and good mechanical properties similar to those of conventional high modulus mixes. However, preparation in non-adapted plants, where RAP is not previously heated, allows a maximum RAP percentage of approximately 30% only.

► Mechanical properties of high modulus mixes with low penetration bitumen and high reclaimed asphalt pavement percentages were evaluated. ► It is possible to prepare high modulus mixtures with high RAP contents and similar mechanical properties to those of conventional high modulus mixes. ► Preparation in non-adapted plants, where RAP is not previously heated, allows a maximum RAP percentage of approximately 30% only.