The effect of aggregate gradation limits consideration on performance properties and mixture design parameters of hot mix asphalt

The main aim of mixture design is to select the best configuration of material in order to achieve mixture fabricating purposes. Aggregate make up a high proportion of volume and mass of mixtures, hence it considered as an important constituent of asphalt concrete. It has been hypothesised that the gradation is an important feature of the aggregate in adoption of optimum mixture. Three gradations are used to manufacture Hot Mix Asphalt (HMA) within special specification band of local code. Rutting resistance was evaluated using the Flow Number (FN) parameter and in order to determine the moisture sensitivity mechanism, a mechanical and visual inspection tests are carried out. The main conclusion of this study is that contrary to customary belief, middle gradation of select band does not produce the best results. Eventually some proposed factors, such as determining "sensitive mixtures" to binder content variation, have been determined for mixture design process.