Question $4$

A new road is to be surfaced using $150/200$ Penetration Grade Bitumen. Aggregates for the double seal surfacing are $13\mathrm{.}2mm$ and $6\mathrm{.}7mm$ respectively. The predicted traffic volume for the road comprises $2400$ light vehicles per lane per day and $215$ heavy vehicles per lane per day. Climate is wet $($and requires an adjustment of $10\%).$ Aggregate properties are: $13\mathrm{.}2mm$ stone: ALD$=8\mathrm{.}2mm,$ flakiness is $10\%$;$6\mathrm{.}7mm$ stone: ALD $=4\mathrm{.}3mm,$ flakiness is $15\%.$ Ball penetration values $($corrected$)$ averaged $1\mathrm{.}5mm,$ gradients are greater than $4\%($and requires an adjustment by $10\%),$ and base texture depth is $0\mathrm{.}5mm.$

Use TRH $3$ to design a double seal of $13\mathrm{.}2mm$ stone and $6\mathrm{.}7mm$ stone, using a $150/200$ Penetration Grade Bitumen for a new road work.

Other details of the road are as follows:

$*$Policy:

Aggregate spread rate: open shoulder$-$to$-$shoulder matrix is preferred $($requires correction of $10\%)$

No pre$-$coating of aggregates $($i$.$e$.$ Tack Coat $=35\%$; Penetration Coat $=35\%$; Fog Spray $=30\%$

$[25$ marks$]$