$($c$)$ HMA mix design involves the aggregate gradation design and determination of the optimum bitumen content $($OBC$).$ Table Q$1($a$)$ shows the test result for ACW$14$ Marshall mix design and Table Q$1($b$)$ shows the test and analysis parameters for asphaltic concrete $[$C$4,$ CO$2,$ PO$2].$

i$.$ Name which road layer that this mix is design for?

ii$.$ Analyze the data, determine the optimum bitumen content for the mix design and check with the specifications.

iii. Comment your answer on $($ii$).$

Table Q$1($a$)$: Sample Test Result for Marshall Mix Design $($ACW$14)$

$\backslash$table$[[\%$ BC$,$Density,TMD$,$Stability $($kN$),$Flow $($mm$),$VTM $(\%),$VFB $(\%)],[4\mathrm{.}00,1\mathrm{.}66,2\mathrm{.}50,15\mathrm{.}77,2\mathrm{.}43,7\mathrm{.}55,50\mathrm{.}5],[4\mathrm{.}50,1\mathrm{.}77,2\mathrm{.}69,17\mathrm{.}58,2\mathrm{.}59,6\mathrm{.}70,61\mathrm{.}1],[5\mathrm{.}00,1\mathrm{.}87,2\mathrm{.}75,17\mathrm{.}85,3\mathrm{.}62,5\mathrm{.}85,65\mathrm{.}5],[5\mathrm{.}50,1\mathrm{.}94,2\mathrm{.}76,16\mathrm{.}25,3\mathrm{.}99,4\mathrm{.}53,71\mathrm{.}1],[6\mathrm{.}00,1\mathrm{.}84,2\mathrm{.}45,14\mathrm{.}33,4\mathrm{.}02,4\mathrm{.}12,75\mathrm{.}9]]$

Table Q$1($b$)$: Test and Analysis Parameters for Asphaltic Concrete

$\backslash$table$[[$Parameter$,$Wearing Course,Binder Course$],[$Stability $($S$),>8000N,>8000N$