EVALUATION OF WARM MIX ASPHALT CONTAINING HIGH PERCENT RAP

Abstract

The Warm Mix Asphalt(WMA) technology has been used worldwide for quite some years, but a few of the concerns associated still remain. Since new additives and new procedures define individual methods and the approach, the characteristics and the properties affected itself becomes a new research. Therefore, it becomes important for the evaluation of the technique to figure out the best possible manner in which the maximum benefit can be derived. The temperature associated with the mixing, compaction reduce dramatically when WMA is used. The same advantage i.e. the reduction of temperature also becomes a concern due to the reduced mixing temperature and the change in properties brought in by this reduction. The lower mixing temperature may not be high enough for the complete evaporation of all the moisture present in the aggregates and this may lead to moisture entrapped in the pavement during construction. Further, the Reclaimed Asphalt Pavement(RAP) is a valuable resource and with proper methods be re-used in the construction of the pavements. RAP used for the study has been obtained from two different source. Therefore, the thesis aims at studying the effect of WMA technology incorporating RAP, with varied in-service aging and aggregate gradation. The gradation used was Dense Bituminous Macadam(DBM)-Grading-II as per MORTH, with varying levels of RAP replacement at 15%, 25% and 35% by weight of the aggregates. The WMA mixes performed better in terms of moisture resistance, however the effect of aging was seen on the moisture susceptibility when the RAP content was increased. The binder blends were also tested for their rheological properties to establish the variation in results due to gradation and aging of the binder. Keywords: Warm Mix Asphalt, Reclaimed Asphalt Pavement, Aggregate Gradation, Binder, Moisture Susceptibility, Rheology.