Evaluation of the addition of short coconut fibers on the characteristics of asphalt mixtures

Abstract

The damage path beginning at the surface layers of the failure receives the load of the traffic and a change in temperature of 20-50 °C. Structural changes in the asphalt mixture cause an increase in the temperature of the surface of the road, approaching the softening point of asphalt. Short coconut fibers are waste from coconut processing, with a length of 5-12.5 mm. The addition of 0.5%, 0.75%, 1%, 1.25%, and 1.50% coconut fiber changed the characteristics of the asphalt. The fiber size was varied (5, 7.5, 10, and 12.5 mm) to determine its effect on the asphalt characteristics. The fiber size variation was also conducted to determine its effect on the asphalt-aggregate mixture at 60 °C using the Marshall immersion test. The addition of 0.75% 5-mm fibers by weight of the asphalt increased the value of the Marshall stability by 10-15% and produced a lower penetration-grade bitumen. The temperature of the mixing fibers in the asphalt must be below the flash point of the fibers during the heating of the asphalt-fiber mixture.

Keywords: coconut fiber, temperature, resilient modulus, asphalt mixtures, Marshall test