Modification of the Properties of Warm Mix Asphalt Using Recycled Plastic Bottles

Abstract

Construction of flexible pavements with hot mix asphalt (HMA) mixtures consumes huge energy which impacts the resources and the environment of the world. Warm Mix Asphalt (WMA) is an effective alternative as they produced with lower mixing and compaction temperature than those used in HMA production. This technology decreases energy consumption, saves money, and reducing the environmental pollution. This technology, if combined with the use of waste materials to improve the properties of WMA, can generate a revolution in sustainable construction. Polyethylene Therephthalate (PET) wastes accumulated over the world increasingly. However, and to the best knowledge of the author, no such research adopts using PET wastes in combination with WMA properties improvement. Therefore, this study covers usage of PET waste bottles to modify the properties of WMA. The study adopted usage of ground PET waste bottles with maximum particle size of 2.36 mm with different contents (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, and 1.1% by the weight of aggregate) to replace an equivalent portion of fine aggregate. The study involved a number of laboratory tests to investigate the effects of different PET content on the properties of WMA. The testing program included Marshall tests and rutting susceptibility tests. The results exhibited significant improvement in engineering properties of the mixtures modified with optimum PET content (which was found to be 0.5%) in terms of increase in stability and stiffness and decrease in rutting susceptibility without adverse effects on the other desirable properties of the mixture.