Impact on methodology for determining absorption in the fine fraction of recycled material from asphalt mixtures

Abstract

One of the most commonly discussed strategies in the construction industry to mitigate the generated environmental impacts is the use of waste, especially that produced on-site.In road engineering, there is a growing trend towards the use of recycled asphalt mix material known as RAP (Reclaimed Asphalt Pavement). This particulate material contains an asphalt binder, so although it is expected that the absorption of the aggregate that makes up the RAP should be reduced, it keeps some remaining water absorption capacity. To evaluate the absorption, the aggregate must be brought to its saturated surface dry condition, which becomes complex to analyze in the fine aggregate (material that passes through sieve No.4 [4.75 mm]). In this paper, this parameter is evaluated in the fine fraction of recycling derived from asphalt mixtures with modified asphalts (RMAP), using two methodologies: the first following the cone method i.e: ASTM C128, IRAM 1520, NTC 237, etc; and the electrical conductivity based on the Japanese standard JSCE-S506-2003. The two are compared, and it is evident which proposed methodology reduces the influence of the operator and impacts of each method. In addition, the results of the recovered asphalt characterization are presented, which, together with the material absorption value, allow thenecessary temperature to be adopted to eliminate the water in the reservoirs of the RMAPs, producing considerable energy savings.