Effectiveness of Liquid Antistripping Additive for Emulsion-Treated Base Layer Using Reclaimed Asphalt Pavement Material

Abstract

In the new global economy, getting natural aggregates (NA) has become a central issue for constructing flexible pavements due to the scarcity of aggregates and the ban on mining in various states in India. This research is an attempt to achieve sustainability by using a liquid antistripping additive for emulsion-treated base layer to improve the performance of Reclaimed Asphalt Pavement Material (RAPM) inclusive aggregates. RAPM was evaluated, with inclusion percentages of 50 and 70 percent, whereas, the control mix was prepared using 100 percent natural aggregate (NA). The effect of inclusion of liquid antistripping additive (ASA) with different RAPM percentages on various properties of ETB mixes, such as maximum dry density, indirect tensile strength, moisture resistance and resilient modulus, was studied. Furthermore, when compared to RAP-ETB mixes without ASA, RAP-ETB mixes with ASA were found to preserve many of their qualities. The present study aimed to propose the laboratory design of optimum bitumen emulsion content (OBEC) for ETB in a simpler manner. For 50 RAP, obtained OBEC was at 4.4%, whereas for 70 RAP, OBEC was obtained at 3.8%. However, for 100 % NA, calculated OBEC was 7.0% as there was 0% RAP in it, hence binder absorption was more. The strength parameter was assessed using the Indirect Tensile Strength (ITS) test. At the same time, the pavement response was measured in terms of Resilient Modulus (MR). MR of 70 RAP mixes was higher than that of 50 RAP mixes, and 100 NA mixes with antistripping additive. Test results were encouraging, and significant improvement in strength was caused by cement filler and antistripping additive.