Toughness Performance of Recycled Aggregates for use in Road Pavement

The policy of driving organization such as Highways Agency is towards the use of performance related specifications. This policy and adoption of European wide aggregate standards on the one hand, and sustainable construction pressures on the other, all strongly emphasize on further need for more developments to specifications and performance assessment methodologies instead of creating barriers to the use of suitable materials. Performance related specifications for pavement foundations are being developed and are primarily based around in-situ control and compliance testing. Laboratory based tools for assessment of the performance of foundation materials and their durability under adverse conditions would be a key factor to the successful use of alternative materials. The toughness performance of recycled concrete aggregates (RCA) mixed with natural aggregates (NA) was evaluated based on the test specifications given in the NCHRP Report 598. For this purpose Los Angeles Abrasion and degradation test results were correlated with established Micro Deval designations in NCHRP report 598.Three main factors involved in performance assessment; i.e. (a) traffic loading, (b) moisture levels in highway pavements and (c) the temperature conditions. The research study showed that the materials were appropriate for unbound subbase for medium traffic in non freezing condition from the standpoint of toughness. Also they are suitable for low traffic situations with low moisture and freezing weather.