Micro Deval Tests-Highway Systems
Suitability of Existing Micro Deval Testing Protocol to Evaluate Durability Road Aggregates
Micro-deval test is a relatively new tool considered by geotechnical and material engineers to evaluate the durability aggregates used in road construction. It is a test based on submerging the aggregates in water for an hour and then tumbling in a chamber with this water and steel abrasion balls for a specific time period or revolution. The tests are performed following ASTM D6928 or AASHTO T327 (identical standards). Initially considered by some researchers as an alternative to Los Angeles abrasion test, by some researchers this test provides a better measure of the aggregate as it involves water. The presence of water minimizes the large impact as observed in LA abrasion test. However, currently only four States in U.S., prescribe the use of micro-deval test to assess the durability of unbound base aggregates. Part of this is because in most cases there is not enough experience to relate the meaning of this test into field performance. This research focuses on developing a methodology to relate the experimental results to long-term field performance and ways to shorten duration of the laboratory tests.
