Feasibility of roller compacted concrete pavement containing different fractions of reclaimed asphalt pavement

Abstract

The present study investigates the optimum fraction of RAP (coarse, fine & total) along with its optimum proportion (50% & 100%) for Roller Compacted Concrete Pavement (RCCP) mixes, based upon various fresh, mechanical and durability properties. The considered properties were optimum moisture content, fresh density, compressive strength, flexural strength, split tensile strength, total permeable voids, water absorption, initial & secondary rate of absorption, and durability properties in aggressive environments of sulfate and chloride ions. Incorporations of any fraction of RAP reduced the fresh properties of the RCCP mixes, however, had less than 4% detrimental effect on the dry density values when compared with the control mix. The compressive strength requirement of 27.6 MPa for RCCP mixes was achieved by all the RAP mixes, except for the mix containing 100% total RAP, however, the same mix achieved the minimum flexural strength benchmark of 3.67 MPa. Additionally, post-failure load carrying capacity of high RAP mixes was observed to be better than the low RAP & control RCCP mixes. Durability results indicated that incorporations of RAP for RCCP mixes could be beneficial, in terms of lower porosity, reduced water absorption, lower initial & secondary rate of capillary water absorption, however, the mixes suffered dramatic losses when subjected to aggressive environments of sulfate and chloride-rich ions. Nevertheless, low proportions of RAP (coarse & fine, separately) may be suggested for these surroundings. Similarly, individual coarse and fine RAP mixes provided with sufficient abrasion resistance depicting their suitability to act as a wearing course of the RCC pavements. Furthermore, incorporation of any fraction of RAP could evidently lower the total production costs of 1 m3 RCCP mix by ∼46% compared to the conventional RCCP mix.