Page 46 - Lecture Notes DCC3113

vii. Elongation Index

To determine percentage of elongated aggregate. An aggregate is
considered elongated when its thickness is more than 1.8 times its
average dimension.

Sample of elongated

aggregate
Figure 3-13: Elongation Index Equipment

viii. Water Absorption and Specific Gravity

To indicate the strength and porosity of aggregate. Aggregate with high specific gravity is
expected to have high strength.

Figure 3-14: Equipment using water displacement method for specific gravity

ix. Coating and Striping

To determine the adhesion of the bitumen and the aggregate with the influence of water

x. Polished Stone Value

This test is only for aggregate to be used for wearing course. PSV indicates the resistance
to polishing effect by traffic.

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