Comparative Assessment of Deformation under Repeated Tensile and Compressive Stresses for Recycled Asphalt Concrete

Abstract

eduction of the consumption of energy and preservation of natural resources are the trends followed globally to attain the sustainability of the infrastructure. The economical and environmentally friendly process for treating Reclaimed Asphalt Pavement (RAP) was followed. In this assessment, an attempt was made to compare the deformation of recycled asphalt concrete mixture under the impact of repeated tensile and compressive stresses. Reclaimed asphalt pavement (RAP) was subjected to recycling with liquid asphalt (cutback and emulsion). Two sets of asphalt concrete cylindrical specimens have been prepared in the laboratory; the specimen of the first set has 63.5 mm height and 102 mm diameter. However, the specimen of the second set has 102 mm height and diameter. The first set practices repeated indirect tensile stresses (ITS) while the second set was subjected to repeated compressive stresses (CS). All the asphalt concrete specimens were tested at 20° C in the Pneumatic Repeated Load System (PRLS). The applied stress level was 0.138 MPa. A constant loading frequency of 60 cycles per minute was implemented and the sequence of loading for each cycle is 0.1 second loading duration and 0.1-second of resting period. The deformation was monitored with the aid of LVDT (Linearly Variable Differential Transformer). It was concluded that the total axial deformation under repeated compressive stresses is higher than that under repeated tensile stresses by (51, 43, and 27) % for reclaimed, recycled with cutback, and recycled with emulsion mixtures respectively. The permanent deformation increases by (20.2 and 29.6) % under compressive stresses and (40 and 93.1) % under tensile stresses when the mixtures are rejuvenated with emulsified asphalt and cutback.