## Materials, Methods and Results
### Results  
The FBB modulus results for the unimproved granular materials are summarised in Table 2. Based on gradation combination theory, the Weipa and Stonemaster granular materials were improved by blending with the Bluerock material, primarily to add coarse aggregate to the gradation. The proportions of the various materials in each improved granular material blend (Table 3) were based partly on judgment, with the aim being to optimise the overall gradation while maximising the marginal material content. The improved granular material gradations were closer to that of the reference (Ayreshire) material, but did not completely replicate it (Figure 3). It is acknowledged that blending marginal materials reduces the volume of marginal material that is used and still requires access to a standard material. However, in this case, the Bluerock material was also deemed to be marginal, although less so than the Weipa and Stonemaster materials, and where the only alternate is complete rejection of the marginal material, using more than 50% marginal material is still attractive. The improved marginal material FBB modulus results are in Table 4.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Property** & **Method** & **Limits** & **Ayreshire** & **Bluerock** & **Stonemaster** & **Weipa** \\ \hline Liquid limit (\%) & Q104A & 25 max & 21 & 19 & 22 & 36 \\ Plasticity index (\%) & Q105 & 10 max & 4 & 4 & 7 & 12 \\ Weighted plasticity (\%) & Q105 & 150 max & 72 & 48 & **175** & **342** \\ Linear shrinkage (\%) & Q106 & 6 max & 3 & 3 & 5 & 5 \\ Weighted shrinkage (\%) & Q106 & 85 max & 52 & 36 & **115** & **140** \\ Fines ratio (\%) & Q103A & 0.30–0.55 & 0.43 & 0.50 & 0.40 & **0.57** \\ \hline \hline \end{tabular} Red italic text denotes properties that fall outside the limits.  
\end{table}
Table 1: Granular material properties.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Granular Material**} & \multicolumn{2}{c}{**3 Days Cured**} & \multicolumn{2}{c}{**7 Days Cured**} & \multicolumn{2}{c}{**14 Days Cured**} \\ \cline{2-7}  & **Cured** & **Saturated** & **Cured** & **Saturated** & **Cured** & **Saturated** \\ \hline \multirow{3}{*}{Stonemaster I} & 4297 & 1865 & 5906 & 3805 & 5496 & 5076 \\  & 4819 & 2218 & 5992 & 3892 & 7552 & 4809 \\ \cline{1-1}  & 4381 & 2387 & 6037 & 4069 & 8242 & 4825 \\ \hline \multirow{3}{*}{Weipa I} & 5414 & 2915 & 6100 & 4165 & 8479 & 6279 \\  & 5182 & 4060 & 6113 & 4743 & 8688 & 5868 \\ \cline{1-1}  & 5822 & 3689 & 6563 & 4686 & 9018 & 5678 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Improved granular material FBB modulus results (MPa).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Granular Material**} & \multicolumn{2}{c}{**3 Days Cured**} & \multicolumn{2}{c}{**7 Days Cured**} & \multicolumn{2}{c}{**14 Days Cured**} \\ \cline{2-5}  & **Cured** & **Saturated** & **Cured** & **Saturated** & **Cured** & **Saturated** \\ \hline \multirow{3}{*}{Ayreshire} & 4458 & 2464 & 7864 & 4583 & 9858 & 5913 \\  & 5959 & 3142 & 7393 & 4738 & 10,176 & 5510 \\  & 5927 & 3177 & 7069 & 4120 & 11,546 & 5656 \\ \hline \multirow{3}{*}{Bluerock} & 3418 & 1862 & 4488 & 2655 & 6259 & 3253 \\  & 3262 & 1931 & 4243 & 2428 & 6202 & 4105 \\  & 3298 & 1870 & 4225 & 2299 & 6401 & 4350 \\ \hline \multirow{3}{*}{Stonemaster} & 3347 & 2178 & 4980 & 2838 & 5703 & 3883 \\  & 3433 & 2070 & 5925 & 2998 & 6022 & 4569 \\  & 3515 & 1855 & 5164 & 3090 & 6695 & 4450 \\ \hline \multirow{3}{*}{Weipa} & 4946 & 1929 & 5446 & 3212 & 8080 & 5099 \\  & 4830 & 2580 & 6111 & 4025 & 7032 & 3965 \\ \cline{1-1}  & 4210 & 3069 & 6284 & 3673 & 6570 & 4859 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Unimproved granular material foamed bitumen base (FBB) modulus results (MPa).  
Figure 3: Improved granular material gradations.