A critical analysis of leaching and environmental risk assessment for reclaimed asphalt pavement management

Limitations on the Use of Recycled Asphalt Pavement in Structural Concrete

“…This indicates that RAP, under most regulatory policies for beneficial reuse of waste in the environment, would pose a minimal risk from a leaching standpoint. Risk evaluation tools, like IWEM (US EPA's Industrial Waste Management Evaluation Model) used by Spreadbury et al [43], could be used to provide estimates on the content of chemical compositions and to evaluate what types of controls may be necessary to verify potential environmental risks. Such estimates can then be supported by field monitoring in order to make definitive conclusions on the actions to be taken.…”

Rheological Evaluation of Softened Binders Blended with Aged Asphalt Selected with a High-Temperature Mixing Chart

“…[ 2 ]. Just 360 million metric tons of asphalt pavement are produced annually in the U.S. [ 3 ], being the world’s most recycled building material, which can be processed and used to replace virgin aggregates and binders [ 4 , 5 , 6 ]. According to the Federal Highway Administration (FHWA), approximately 100 million tons of hot mix asphalt (HMA) are produced each year [ 7 , 8 , 9 ], as it is the most widely used paving material in the world [ 4 , 10 ].…”

“…Thus, the road sector is moving towards sustainable development, as it aims to reduce the consumption of nonrenewable resources [ 5 , 11 , 12 ] through reclaimed asphalt pavements (RAP) [ 2 ]. These are removed materials, consisting of granular pieces of milled asphalt pavement [ 3 , 10 ] of high quality and well graded [ 9 ]. RAP can be extracted by central plant hot recycling (CPHR), hot in place recycling (HIR), central plant cold recycling (CPCR), and cold in place recycling (CIR) processes [ 13 ].…”

“…In addition, the NCHRP project D9-12 determined that the RAP content is between 10% and 20% [ 5 , 6 ]. On the other hand, several studies have reported using RAP at rates between 20% and 50% [ 3 , 7 , 14 , 15 , 16 ], but some studies have demonstrated the feasibility of producing asphalt mixtures containing high (40%) or very high (100%) RAP contents [ 5 ]. An analysis of the volumetric properties and performance of asphalt mixtures was carried out by Antunes, Freire and Neves [ 4 ], which showed fourteen case studies in which RAP was used at rates of 10% to 40%, 10% to 60%, and 100%.…”

“…Consequently, if 100% of the RAP is used, the need for virgin materials would be reduced, thereby inducing sustainability in pavements [ 11 ]; hence, RAP has been widely used because it helps to reduce costs in the construction of flexible pavements, conserves natural resources [ 4 , 8 , 17 , 18 , 19 , 20 ], requires low amounts of energy and fuel [ 1 , 9 ], eliminates solid waste, and reduces the carbon footprint [ 3 , 10 , 11 , 12 ]. In this sense, according to Debbarma and G. D. Ransinchung [ 21 ], there were reductions of 67% and 18% in cost and gas emissions, respectively, when RAP was used in asphalt mixtures, while CO 2 emissions were reduced by 2%.…”