DESIGN COMPATIBLE CONTROL OF BASECOURSE CONSTRUCTION.

This paper addresses the problem of controlling basecourse in such a way as to reflect the specific design objective of adequate strength. Strength criteria for basecourse quality are reviewed and discussed in relation to the recommendation of recent publications and the introduction of the Impact Soil Tester. Correlations between California Bearing Ratio, Texas Class Number, Elastic Modulus and Impact Value based on laboratory test data are presented and related to published data. Compaction objectives are considered in relation to strength requirements and control by in situ strength testing. The significance of variability is emphasized and an example of strength contour plotting by computer is given. A procedure for control based on a target strength and minimum coefficient of variation for a given compactive effort is presented. Refs.