RELATIONSHIP BETWEEN WORKABILITY AND MOISTURE-INDUCED DAMAGE OF ASPHALT CONCRETE MIXTURES

This paper details a laboratory study which aims to understand the relationship between moisture-induced damage and torque in asphalt concrete mixtures. Research was conducted using three different gradations of dense asphaltic concrete mixed at two different temperatures of 140oC and 155oC. Torque readings were measured using a transducer at different temperatures while compacting the mixtures using a gyratory compactor and these were logged using a software. Indirect tensile strength tests were conducted on these samples for both dry and wet conditions to obtain the tensile strength ratio (TSR). The findings suggest that any increase in the value of torque will result in the decrease of Tensile Strength Ratio (TSR). This research also found a significant relationship between torque and TSR; all the variables (TSR, mixing and compaction temperatures) significantly influenced torque. This implies that any increase in TSR at different level of mixing and compaction temperatures will decrease the value of torque. The findings from this research can be used as guidance on workability for the asphalt industry.