Sustainable Urban Surface Asphalt Layers

Abstract

Nowadays, given the current growing awareness about the preservation of the environment, asphalt technicians are assessing and trying to correct resulting impacts from the manufacture and application of bituminous mixtures. The concept of sustainability has come to the field of bituminous mixtures with two main components: reducing emissions and reducing the consumption of raw materials, preserving resources for the future. Conservation and rehabilitation activities of road pavements generate an increasing amount of waste from the milling of the layers of damaged asphalt mixtures. This material, which has great costs and exceptional properties, should be reused in manufacturing new mixtures of the same type and function. Moreover, it is necessary to reduce the emissions from the manufacturing and application of asphalt mixtures. This paper presents the efforts carried out to develop a technology that allows manufacturing and applying half-warm mix asphalt in surface layers of low speed roads at low temperatures using high percentages of reclaimed asphalt pavement. The research project focused on designing asphalt mixtures to be placed in urban areas. Continuously graded mixtures were manufactured at 100 °C and compacted at 80 °C with different percentages of RAP, ranging from 50 to 100 %. The results obtained from testing laboratory specimens indicated that their mechanical properties, regarding cracking resistance and fatigue resistance, were very close to those expected from regular HMA mixtures.