Fatigue Life Assessment of Modified Asphalt Concrete

Fatigue life is affected by the growth and accumulation of cracks, under the action of repeated vehicular loading, aging and effect of the environment. The main objective of the study is to provide a comparative evaluation of pavement fatigue life between modified and conventional asphalt concrete under the influence of changing the percentage of asphalt content by (0.5% ±) of the optimum, changing the testing temperature and under long-term aging and moisture damage impacts. Asphalt cement with a penetration grade (40-50) and aggregate with nominal maximum size of 12.5 mm, filler and two types of additives, fly ash and silica fumes have been implemented. Slab samples were prepared using the roller compactor device, Beam specimens were obtained by cutting each slab to five beams of 400 mm x 60 mm x 50 mm size. Beams were tested using Nottingham four point bending beam device under the influence of three levels of microstrain (750, 400, 250), and different testing temperatures (5, 20, 30) ° C. Beams were also exposed to long-term aging and moisture damage impacts. Keywords: aging, asphalt concrete, fatigue life, fly ash, moisture damage, silica fumes