Evaluation of Bituminous Mix Characteristics Prepared with Laboratory Developed High Modulus Asphalt Binder

Abstract

Asphalt layers in India are widely constructed with the use of viscosity grade binder. The mixes prepared with this binder exhibit early distress because of uncontrolled heavy axle loads and high ambient temperature. Pavement engineering specialists are in search for improved performing pavement materials, more specifically on the top layer. As a matter of fact, the viscosity and stiffness of the asphalt binder play a critical role in the overall performance of pavements at elevated temperatures. The stiffer or hard binder shall provide solution for improving the performance. This article aims in evaluating the performance characteristics of high modulus asphalt concrete (HMAC) mixture from the laboratory-developed high modulus asphalt binder (HMAB). The HMAC mixes prepared with HMAB require a penetration value of 10/20 or 15/25 at 25 °C. The development of HMAB is assessed from the following laboratory tests (1) physical, (2) chemical and (3) rheological, while that of HMAC includes (1) Marshall properties, (2) tensile strength, (3) immersion-type rutting characteristics, and (4) resilient modulus tests. The developed HMAB has shown an increased performance grade (PG) of base binder from 64 to 76 °C. HMAC mix has shown remarkable resistance toward the permanent deformation than the base mix. Moreover, the resilient modulus of the HMAC was found to be improved by twice that of the base mix. Further, a pavement section model was designed for traffic of 300 msa, and the model performance was evaluated using IITPave and finite element analysis. HMAC pavement section was found to be more economical than pavement prepared with the base mix. The outcome of this study is expected to help pavement engineers and other agencies in the revision of guidelines for possible inclusion of polyphosphoric acid as an approved modifier for the production of HMAB.