A Simple Relationship to Estimate Parameters of the Optimum Compaction Point

Abstract

Compacted clay covers have been the most commonly used materials for hydraulic barrier layers. During their construction, the control of some parameters such as compactive effort and molding water content is required. These last parameters affect the hydraulic conductivity, which is considered as one of the important key parameters for cover design. To reach the target in terms of hydraulic conductivity, the cover must be compacted to a pre-determined dry unit weight that usually corresponds to a certain percentage of the maximum dry unit weight (γdmax). During the prefeasibility stage of a project (before conducting the required tests), γdmax and the optimum water content (wOpt) can be estimated to obtain an early overview of the conditions that can be anticipated. In this regard, a new approach was proposed to estimate these parameters using the liquid limit (wL) and the plastic limit (wP). The proposed equations were developed using data from 56 compacted clay liners and validated using 44 others taken from published data. Results presented in this paper indicate how the proposed equations can successfully estimate parameters of the optimum compacted point.