Deformation of Stone Matrix Asphalt and Porous Asphalt Concrete under Repeated Load

Abstract

The resistance to deformation of asphalt concrete pavement in general depends on the gradation of aggregates, voids, and binder content. Stone matrix asphalt and porous asphalt mixtures are considered as a sustainable choice for heavy duty pavement surfacing course. Such pavement layer practices heavy repeated loading and is expected to sustain the load and exhibit control on deformation. In the present investigation, the permanent microstrain under repeated compressive stresses of stone matrix asphalt (SMA) and porous asphalt mixtures was assessed and compared. Stabilizing additives such as fly ash and carbon fibers have been implemented to control the deformation and the drain down of the binder for both mixtures. It was observed that the total microstrain of SMA declines by (11.4, 31.6, and 8.8) % under (0.068, 0.138, and 0.206) constant stress levels after implementation of fly ash. However, the total microstrain of porous asphalt declines by (16.9, 17.8, and 10) % under (0.068, 0.138, and 0.206) constant stress levels after implementation of carbon fibers. It was concluded that SMA mixture exhibits lower permanent microstrain than porous asphalt mixtures regardless of the implemented additives or the constant stress levels.