Optimization of the resilient modulus of the surface and base layers using a SBS polymer

Abstract

Most roads in Iraq suffer from persistent problems and permanent deformations which can be attributed to poor of materials used, lack of specifications & poor quality and may be because of heavy loads, because of these problems increased research and reports specialized in improving the quality of materials used to reduce the deformations occurring in pavement, especially the ruts. This research uses SBS polymer at 4% of asphalt cement weight and at air temperatures of ($20^{\circ}C, 40^{\circ}C$, and $60^{\circ}C$) to improve the resilient modulus, which is a key factor in reducing permanent deformations of the surface and base layers. The results showed that the surface layer’s resilient modulus increased by (25, 58, and 13.6%) for temperatures of (20, 40, and 60 degrees Celsius) and the base layer’s increased by (50, 81, and 36) % for the same temperatures. This increase in the resilient modulus increases the resistance of the paving layers to high temperatures and traffic loads, thus reducing the effect of permanent deformations and increasing the service life of the road