The main objective of this innovation is to develop bituminous underlayers (sometimes called base course) with high percentage of re-use materials at low cost and with high performance. In fact, this innovation concerns the formulation and assessment of high performance underlayers (high modulus asphalt – HMA) with high percentage of reclaimed asphalt. Nowadays, high performance underlayers are rather common, however the percentages of reclaimed asphalt (RA) in such mixes is until now very limited.