Associate professor, Kuwait University,
Pages: 15 Published: Jan 1984
This paper discusses a method of evaluating the compaction characteristics of asphalt concrete mixtures in terms of a coefficient of compactibility or resistance to compaction. Two types of asphalt concrete mixtures have been considered in this study: one is a conventional type with an asphalt cement 60/70 penetration, and the other is an extended sulfur asphalt concrete with 40/60 sulfur to asphalt (S/A) ratio by weight. The effect of mix variables, such as filler content and binder content, is included in the experimental program. Marshall specimens for each mix were subjected to different compaction levels varying between 10 and 100 blows on each face. Bulk density and voids content for each mix at each compaction level were determined. Each specimen was then tested for creep at 40°C under a controlled constant stress (0.1 N/mm2) for 30-min load duration.
Based on the experimental data and using linear regression analysis a relationship between compactibility and stiffness characteristics for each mix is established, which is important in controlling the permanent deformation distresses. The results of this study show that the specifications requirement for a certain percent of laboratory compaction would not be adequate for predicting permanent deformation of the asphalt pavement layer. An additional requirement, such as resistance to compaction, may correlate better with the actual performance of the tested mixture under appropriate conditions of environment and traffic.
bituminous paving mixtures, binders, sulfur, asphalt content, laboratory compaction, compaction effort, compactibility, air voids content, density, stability, creep, stiffness
Paper ID: STP32505S