Page 68 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

The test described above will be conducted in accordance with procedures established
by Malaysian Standard (MS), British Standard (BS) and the American Society for Testing
Materials (ASTM).

Marshall Stabilitytest should be conducted to determine optimum bitumen content of the
mixture to be used so that the mixture obtained is a good mix in terms of workability levels
and also in terms of structural strength. In Marshall stability test, we will make several different

bitumen premix sample and all premix samples will be tested for its stability and flow. These
values will be compared in six graphs to select the optimal bitumen that has the best
stability value. The average values of bulk specific gravity, stability, flow, VFB and VIM
obtained above shall be plotted separately against the bitumen content and smooth

curve drawn through the plotted value.

Densit Stabilit Flo VIM VF

% Bitumen

Five different types of graphs in Marshall Design

Themeanoptimumbitumencontentshallbedeterminedbyaveragingfiveoptimum
bitumen contents so determined as follows;

a. Peak of curvetaken fromthestability graph
b. Flowequals to3 mmfromthe flowgraph

c. Peak of curvetaken fromthebulk specific gravitygraph
d. VFBequalsto75%forwearingcourseand70%forbindercoursefromtheVFBgraph
e. VIMequalsto4.0%forwearingcourseand5.0%forbindercoursefromtheVIMgraph.

3.0 EQUIPMENT

• Test Machine Marshall
• Head of steeltesting
• Water isotherms (waterbath)
• Extrusion Jack
• Marshall CompactorMachine
• Oven
• Weighing Scale Marshall Testing Machine

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