Effect of water flow within the surface HMA layer on Performance

Abstract

One of the main causes of early failure of paving is water flow within its surface layers. In this study, a new experimental work has been proposed to increase the permeability coefficient using two specifications aggregates (G₁ and G₂) and to increase the coarse gradient ratios subjected to the scrb2003 limits. This enables the angularity of aggregates to maintain coherence and to ensure acceptable stability characteristics. In order to accomplish this purpose, several models have been prepared to study the effect of increasing proportions of coarse aggregate on the properties and whether they serve the desired purpose. The results showed an increase in the stability of G₂ in general in contrast with the results of G₁.  The permeability coefficient also increased for G₂ mixtures by 0.005.  Indirect tensile testing demonstrated an increase in T.S.R of 10.5% for the specification of G₂.