Effect of olive waste ash on properties of asphalt cement and asphalt concrete mixtures

Abstract

In this study, the effect of olive waste ash on the properties of asphalt cement and asphalt concrete mixtures was investigated. Asphalt cement with (80/100), limestone and valley gravel aggregates, and olive waste ash were used. Five asphalt binder levels with (0, 5, 15, and 20) percentages of olive waste ash (OWA) by volume of asphalt-ash binder were performed to investigate the effect of OWA on the physical properties of the asphalt-ash binder. Penetration, softening point, ductility, fire and flash point, and the specific gravity were performed on the binder. Five levels of asphalt-ash binders were used to investigate the Marshall specimens and the dynamic creep tests. These tests were performed at three testing temperature (20, 30, and 40°C) and three load frequency levels (1.0, 4.0, and 8 Hz). The results showed that penetration and ductility inversely related, while, specific gravity, softening point, fire and flash point were directly related to the increase in OWA content. For both aggregates of asphalt concrete mixtures, as the percentage of ash increasing, unit weight and flow were decreased for the same volume of asphalt-ash binder content for each type of aggregate, while, as the percentage of OWA increased, voids in mineral aggregate and air voids were increased for the same volume of asphalt-ash binder content for each type of aggregate. Marshall Stability increased up to 10% of OWA, over that the stability decreased. The retained Marshall stability ratio increased with increasing ash, while the dynamic modulus was decreasing with increasing the percentage of OWA content, testing temperature, and loading frequency for both aggregates.