First Studies about RAP of a Hot Mix Asphalt with Modified Bitumen (RMAP), in the new hot mixes asphalt production

Abstract

The road transport system plays an important role to growth and development of the countries. Most of the national roads are made with flexible pavements. The conventional method of manufacturing hot asphalt mixes uses two non-renewable resources such as stone aggregates and asphalt. This study analyse the use of hot recycling of an asphalt mix, which reduces the use of the new materials, thus encouraging the development of the so-called “circular” economy. In particular, this RAP is derived from an asphalt mix with polymer modified asphalt and is called “RMAP” (modified, “M”). In the Road Research Center’s labratory LEMaC-CIC-PBA there are three different typs of RMAP. On this occasion, the preliminary results derived from the characterization of the component materials for the preparation of a dense hot mix CAC D19 with 25% RMAP1 by weight are presented, using a CA-30 as a virgin asphalt binder. This RMAP until its milling period has a service period of approximately ten years. To obtain the aged asphalt a Rotovapor was used. The percentage of aged asphalt by weight of RMAP was also obtained, which was verified with the calcination test. With the aged modified asphalt, the following tests were carried out: penetration, softening point, rotational viscosity with the Brookfield viscometer and the torsional elastic return in particular, to evaluate the presence of elastic properties according to their origin. The results are presented that show, despite being aged, the asphalt cement still contains higher benefits compared to a RAP derived from conventional mix asphalt, in addition to the notable reduction of asphalt and virgin aggregate in the production of new hot mixes.