Experimental Investigation of the Effect of Types of Fillers on the Performance of Microsurfacing Asphalt Mixture
Aida Fooladi, Saeid Hesami
Abstract
As preservative asphalt, microsurfacing is an effective solution in preventive repair and maintenance, which consists of well-graded fine aggregates, polymer-modified cationic bitumen emulsion, water, and chemical additives in order to control the breaking time of bitumen emulsion. Due to the use of polymeric bitumen emulsion and fully crushed aggregates, these mixtures produce an increase in shear strength, abrasion resistance, and rutting resistance of asphalt surfaces. According to the researches conducted and the substantial role of filler in the strength of asphalt mixtures, and also owing to environmental impacts and high energy consumption of traditional cement filler. In this study, three mixtures containing fillers (microsilica slurry, quicklime, and combination of cement and quicklime) with slow setting bitumen emulsion, and the mixture of cement filler, as the control mixture, were used for laboratory survey and comparison of the effects of different fillers on the performance of microsurfacing asphalt mixture. Based on International Slurry Surfacing Association (ISSA) A143 guideline and ASTM D6372 standard, the performance of samples was assessed by wet cohesion, wet track abrasion, and loaded wheel tests. The findings demonstrate that the utilization of alternative fillers has a better performance in rutting, stripping, and abrasion compared to the control mixture owing to their appropriate physical, chemical, and mechanical features.