Evaluation of Elastic Modulus of Crushed Stone Base Layers for Compaction Control

Abstract

Construction of high-quality crushed stone layers is referred to as “an art and one that is not profusely found today”. Conventional acceptance control procedures only confirm densification of the layer and other fundamental material properties with no direct measurement of strength. As a result of this there appears to be a missing link between design requirements and acceptance control. Slushing is required during the construction process to lock up the aggregate, ensuring stability and a good distribution of the fines through the layer. This study endeavours to confirm whether there is a significant difference in the Elastic Modulus of crushed stone layers before and after the slushing process and to investigate cost effective and appropriate means of controlling this. Preliminary results suggest that poor workmanship can be clearly identified and an increase in Elastic Modulus can be confirmed following the right construction methods and procedures.