Marshall Mix Design Info Sheet

Marshall mix design is a widely implemented method to determine the optimum asphalt content (OAC) prior to the road construction.

Test specimens with different asphalt binder content are prepared. The specimens should then be weighed to ease the calculation for important parameters such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA) and voids filled with asphalt (VFA).

The specimens are first compacted using Marshall hammer before they are being tested for Marshall stability and flow.

The test results and calculated parameters are then plotted against asphalt binder content.

From the plots of bulk density, Marshall stability and VTM, we determine individual OAC values based on individual criterion. The value of OAC for the asphalt mix would be the average of these three values.

It is important to note that, all parameters should be checked against the limits and criteria set out by relevant authorities for various purposes.