Effect of Using Sludge Waste Containing Calcium Carbonate on the Properties of Asphalt and Hot Mix Asphalt Mixture

Abstract

Fatigue failure is one of the common forms of distress in asphalt pavements and manifests itself in the form of cracking under repeated traffic loading or a series of temperature fluctuations/variation in the pavement. It is caused by gradual buildup of irrecoverable strains under repeated loading, which develop into a measurable rut (permanent depression along the wheel path). These strains are due to the visco-elastic response of bituminous materials to dynamic loading. Unmodified bitumen lacks the balance between the visco-elastic response and the increase of the traffic volume. Therefore, binders were modified to face the load and weather challenges. Modified bitumen introduces advantages to the field of highway construction, by improving pavement performance as well as extending the pavement life. Recently, numerous waste materials have resulted from manufacturing operations, service industries and household in which several millions of non-biodegradables are produced. If not taken care of they will persist in the same state for a considerable time and thus cause hazardous problems to environment and human life. Therefore, in the present work, an attempt is to use sludge containing calcium carbonate (CaCO₃), which is a waste product from industry as an asphalt modifier. This will contribute to the utilization and effective disposal of waste sludge. The effect of using lime modified asphalt in bituminous mix is the main thrust of this research work.