ABSTRACT
It is well known that in the CIR process foamed bitumen glues together granulated pieces of Reclaimed Asphalt Pavement (RAP) rather than causing a complete remix of the bituminous mixture as with hot mixes or other processes which use bitumen emulsion. It is for this reason that foamed bitumen mixtures performance are strongly influenced by RAP percentages (Ruenkrairergsa et al. 2004). At the optimum content of foamed asphalt, although mixtures with higher percentage of RAP produce lower indirect tensile strengths, their retained strength, under influence of water, is higher. On the other side, 50% RAP mixtures produce higher resilient moduli, longer fatigue resistance and lower permanent deformation than those with higher RAP percentages. Based on these known results, foam bitumen mixtures are usually produced by using about 50% of RAP and 50% of reclaimed or new crushed stone.
