Characterization of asphalt concrete for its use as landfill liners

This study proposed a landfill system made of asphalt concrete (AC) that was shown to be effective to provide a strong and durable impermeable liner. Comprehensive design procedures for AC liners were developed and critically evaluated. The engineering properties of aggregates and binder required for AC liners were tested and discussed in detail. Contrary to the traditional Marshall method for pavements, five mix criteria were established to examine AC liners used in landfills: permeability, air void, binder content, indirect tensile strength and resilient modulus. Extensive tests were further conducted to determine the engineering properties and durability of AC liners. Results implied that polymer-modified AC had the ability of resisting the attack of leachate, thus retaining the integrity of AC as a liner. For practical applications, design charts were developed for engineers to decide the thickness of AC liners.