Optimization of HMA's gradation design

In order to optimize the Hot Mix Asphalt's(HMA) aggregate gradation,improve the pavement anti-rutting performance,and prolong the pavement life,through single-factor-skeleton-dense-test and Bailey method,the optimal framework structure of gabbro AC-16 gradation was got by analyzing the effect of the aggregate content,CA ratio,passing percent of the key sieve to the gradation's skeleton.The optimal framework gradation is 5.4(19~16 mm)∶30.6(16.0~13.2 mm)∶24(13.2~9.5 mm)∶40(9.50~4.75 mm),the CA ratio is 0.67.The pavement performances(high temperature performance,low temperature performance and water stability) of the optimal gradation and the specification's gradation were studied.The results show that the optimal gradation can improve the pavement performances greatly.8 tabs,4 figs,10 refs.