Efecto del agua sobre el asfalto y su posible influencia en el daño por humedad en una mezcla asfáltica porosa

Abstract

One of the main forms of distress in asphalt mixtures is the moisture damage. This phenomenon occurs mainly when the asphalt binder is separated from the stone aggregate due to water presence. Many studies have been performed to describe and measure the moisture damage resistance in asphalt mixtures. Despite the high number of research projects performed, this phenomenon has not been fully understood yet. A laboratory study was initiated to investigate the influence of the asphalt binder on moisture damage, due to the effect of water only. Physical (softening point-ASTM D36, viscosity-ASTM D-2171, AASHTO T-316 and penetration-ASTM D-5), chemical (SARA-ASTM D-4124) and rheological (AASHTO T 315-05) properties of two asphalt binders (AC 60-70 and AC 80-100) immersed in water during 12 to 17 months were evaluated. Mechanical characteristics of a porous asphalt mixture immersed in water, and manufactured with asphalt binders also immersed in water were evaluated using Marshall (AASHTO T 245-97, 04) and Cantabro (NLT 352/86) tests. As concluding remark is reported that the interface asphalt binder-aggregate stone is affected for the change in the consistency that undergo the asphalt cements in presence of the water. Additionally, binders in presence of water undergo, inside the mixture, contraction, which may be one of the causes generating the stripping phenomenon.