Rheological Properties of Bitumen Containing Organic Foaming Agent for Warm Mix Asphalt

Abstract

Pavement industry is placing more emphasis on incorporating the sustainability in road construction. The construction of road contributes to global warming in terms of greenhouse gas emissions. Generally, the construction of roads adopt hot mix asphalt (HMA) that requires high energy consumption and also lead to environmental pollution. Since last decade, warm mix asphalt (WMA) technology is an attempt to address the aforementioned energy and environmental problems by reducing the harmful emissions and energy consumption. This study investigates the effect of organic foaming agent zeolite on the rheological properties, mixing temperature and compaction temperature of bitumen used in WMA. Dynamic shear rheometer (DSR) characterization is performed to determine the effect of zeolite on complex modulus (G∗), phase angle (δ) and Superpave rutting parameter (G∗/siRΔ) of bitumen. In addition to that, viscosity characterization using Brookfield rotational viscometer is conducted to determine the mixing and compaction temperature. Rheological characterization of binder containing zeolite shows the improvement of elastic segment and short-term ageing resistance. Viscosity characterization reveals that the addition of zeolite in bitumen offers significant reduction in mixing and compaction temperature. Based on the findings of this study, 3 % zeolite can be added to WMA technology as optimum additive content in order to reduce the energy consumption and improve the workability of road construction thereby promoting sustainability in pavement industry.