720468System for Processing of Reclaimed Asphalt Planings (RAP) for High Percentage Incorporation of RAP in new lay road surfaces (Infrarap)ClosedGRD Development of PrototypeInnovate UKCurrently, asphalt removed from a road is stockpiled for later use as aggregate for new hot mix asphalt (HMA) at an asphalt plant. This reclaimed material, commonly known as RAP – recycled or reclaimed asphalt planings, is crushed to a consistent gradation and added to the HMA mixing process. Asphalt consists of 95% aggregate and 5% bitumen, both of which are valuable resources with high embedded energy and CO2 footprint. Several in-situ and ex-situ recycling techniques exist for asphalt recycling the most common of which introduces RAP using a cold feed which bypasses the drying drum. Due to the high moisture content, very low volumes (~20%) are re-used at a significantly high energy cost because the virgin aggregate must be heated to 200-300 deg C. There are also significant issues with the quality of the final product as the aged bitumen binder is damaged by the high temperature needed to dry the virgin aggregate and becomes susceptible to UV degradation and is rendered liable to early stone loss and cracking. The Infrarap project aims to develop a system for processing RAP so that higher percentages can be incorporated into paving materials and especially into the wearing course layer. The system will comprise adaptable heating, mixing and conveying systems which will feed RAP at an optimum low temperature into elevating skips or direct to a mixer-feed chute via a conveyor of a static mixing plant or a mobile mixing plant using an efficient rejuvenator which will allow high percentages of RAP to be recycled into asphalt mixes at low temperatures. The development follows some preliminary investigations into current methods of incorporating RAP into mixes, including alternative systems. There is a clear market need for an independent method of heating and directly feeding RAP into the pug-mills of mixing plants that bypasses a drying drum and obviates all adverse issues with scorching RAP and blocking filters and screens.