Abstract:
The properties of Hot Mix Asphalt (HMA) paving materials depend upon the mixing temperature and compaction temperature. In determining the Optimum Binder Content (OBC) during designing of Hot Mix Asphalt (HMA) by Marshall Method, the mixing temperature and compaction temperature shall be kept 160 ̊C and 140 ̊C respectively. The density voids analysis of laboratory compacted Marshall Specimens depends upon the compaction temperature. To understand the acceptable range of laboratory compaction temperature during designing of HMA, the present study was undertaken.
The design of Bituminous Concrete (BC) which is most commonly used HMA as surface course was carried out by Marshall Stability method and Optimum Binder Content (OBC) was determined at compaction temperature of 140 ̊C. At OBC, Marshall Specimens at different compaction temperatures such as 140 ̊C, 125 ̊C, 110 ̊C, 95 ̊C and 80 ̊C were prepared and tested to find the Marshall arameters.
On the basis of test results, it has been observed that there is minor variation in the properties of mix by decreasing the compaction temperature from 140 ̊C to 110 ̊C, however drastic change in the properties of the mix has been observed as compaction temperature falls below 110 ̊C. On the basis of this study it has been suggested that during evaluation of various properties of HMA in the laboratory, due consideration should be given to compaction temperature otherwise the results would not show true behavior of HMA.
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