Mechanical Performance of Asphalt Mixtures with Natural Aggregates and Recycled Aggregates for Surface Course

Abstract

The recycled aggregates of construction and demolition solid waste can be used on pavements to decrease environmental impacts in cities. Thus, this study aimed to compare the mechanical performance of asphaltic mixtures made with natural aggregates and concrete recycled aggregates for surface course of pavements. The materials were collected in an asphalt mixing plant and in a construction and demolition solid waste recycling plant located in João Pessoa/PB, Brazil. The Marshall asphalt mix design was chosen to determine optimum asphalt content and evaluate mechanical performance of asphaltic mixtures. The asphalt mixtures specimens were composed of natural aggregates, and afterwards of recycled aggregates with percent contents of 25, 50 and 100. The optimum asphalt contents were 5.7 and 7.5%, Marshall stability of 1,070 and 790 Kgf, flow of 6.2 and 5.7 mm for natural aggregate asphalt mixtures and asphalt mixtures with 25% recycled aggregates, respectively. Moreover, percent air voids and percent voids filled with asphalt met the Brazilian DNIT: ES 031/2006 specified standard. However, the asphalt mixtures with 50 and 100% recycled aggregates did not meet the specified standard. Therefore, it was concluded that the replacement of natural aggregates with 25% recycled concrete aggregates in asphalt mixtures can be technically viable to build asphalt surface course on pavements, besides lowering pavement costs and decreasing environmental impacts.

Mechanical performance of half-warm mix recycled asphalt mixtures containing total rates of reclaimed asphalt pavement for their use in road pavements

“…Nevertheless, for the Marshall flow number, it was observed that 5.0% (of total weight of aggregates) was slightly lower than the minimum threshold values (2.5-3.5 mm) stipulated by the Spanish technical specifications (Spanish Ministry of Public Works, 2015) and others researchers (Behnood et al, 2015;Djakfar et al, 2015;Hou et al, 2017;Marques et al, 2014;Pasandín and Pérez, 2013;Pérez et al, 2013;Rafi et al, 2011) and that the more the bitumen content added into the preliminary mix design, the better the mixture behavior (when it is loaded during the Marshall stability test), except for 6.0% binder content. Therefore, it can be concluded that 5.5% binder content (of the total weight of aggregates) was discarded for this research study since it delivers/offers much lower mechanical performance properties in terms of rutting with the wheel tracker (EN 12697-22:2008+A1).…”