Flexural Behavior of Warm Mix Asphalt Concrete

Abstract

Research work on implementation of Warm Mix Asphalt (WMA) for roadway paving has been undertaken by many researchers due to its beneficial impact on the environment and reduction in the fuel consumption. In this investigation, two WMA mixtures have been prepared in the laboratory using medium curing cutback (MC-30) and Cationic emulsion. Hot mix asphalt (HMA ) mixture was also prepared for comparison. Beam specimens of (380 mm) in length, (80 mm) in width and (50 mm) in height were constructed form the mixtures and subjected to flexural fatigue test under repeated flexural stresses through the four-point loading technique at 25°C. Test results were analyzed and compared. It was concluded that HMA specimen can sustain more than 100% of load repetitions to failure higher as compared to the two types of WMA, On the other hand, the tensile strain of WMA with cutback and emulsion was (37.5 and 54) % lower than that of HMA respectively. Emulsion exhibit more susceptible behavior to asphalt content variation as compared to WMA-cutback or HMA. A sharp reduction in the stiffness rate could be noticed for WMA mix with cutback as compared to the gentle reduction in the case of WMA mix of emulsion and HMA. For HMA and WMA it was found that the resilient modulus decreased by a range of (4–20) % when the asphalt content increases or decreases by 0.5% from its optimum requirements.