THE EFFECTS OF (RAP) ON THE LABORATORY PERFORMANCES OF HOT MIX ASPHALTS

Document Type : Original Article

Authors

1 M.Sc. in Civil Engineering (2010) – Cairo University – Egypt

2 Highway and Traffic, Eng., Public Works Department, Faculty of Eng.Cairo University

Abstract

The use of reclaimed asphalt pavement (RAP) in flexible pavement surface layer has been a major sensitive issue in the construction industry. Due to limited space available in landfills, the amount of high quality virgin aggregate declines, and the high price of oil, the use of RAP in new asphalt concrete mixtures has become very attractive. This research has been conducted to study the laboratory performances of HMA mixture containing RAP, in which Marshall properties and resilient modulus characteristic were evaluated [4,6,7]. A Marshall mix design mixture containing 0% RAP with binder (60/70) was used as the control mixture for evaluating properties of mixtures containing 25% and 40% RAP. Marshall tests and Indirect Tensile Modulus (Resilient Modulus) were performed on samples of the three mixes. Comparing the results of the conducted tests indicated that the use of RAP in Hot Mix Asphalt (HMA) was advantageous in all properties measured. The mix containing RAP showed reduction in Marshall Stability, indirect tensile value, and Resilient Modulus, and the higher the temperature the lower of resilient modulus values, but the results are acceptable by Egyptian code specifications. Therefore, it is preferred to use mixes containing RAP in highways with studied proportions.

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