Models for estimating optimum asphalt content from aggregate gradation

Abstract

The optimum asphalt content is one of the most important parameters as it has a great influence on the asphalt-mix performance. This paper provides a set of simple and multiple linear regression models for estimating the optimum asphalt content (OAC) from the aggregate gradation of the asphalt mix. The process of estimating the OAC is called the asphalt-mix design. The method used for the mix design in Egypt is the Marshall design method; however, the results are subject to variation and it is time consuming as it involves preparation and testing of 15 specimens. This research study provides a new approach for using the Marshall test; this approach is time saving and reduces the effort and resources used in the test as the developed models can be used to estimate the OAC and then three Marshall specimens are prepared to estimate the other design parameters.