Application Of Clegg Impact Value For The Evaluation Of The Properties Of Asphalt Concrete

The Clegg impact hammer is used to obtain a parameter relating to strength or stiffness of soil or similar type of materials. The parameter obtained is called the Clegg impact value (CIV). This study has investigated the relationship between CIV and bitumen content in a compacted bituminous concrete and the possible application of CIV for the evaluation of the properties of asphalt concrete. It was found that the CIV of compacted asphalt increases to a maximum value and then decreases with an increase in bitumen content. This relationship was similar to the stability versus bitumen content relationship determined in the Marshall method of mix design. Optimum binder contents determined using CIV, air voids and bulk density were comparable with those values determined using the standard Marshall method and the Austroads Pavement Research Group method.