Mechanical Characterization of Lightweight Expanded Clay Aggregate Materials for Modeling Their Geotechnical Behavior

Abstract

Based on an extensive testing program, this study presents the mechanical behavior of a lightweight expanded clay aggregate (LWA). This material is currently being used in many civil engineering works and particularly in geotechnical applications due to its low weight, high shear strength, and favorable drainage characteristics. The present investigation is based on a particulate mechanics approach aimed at the quantification of appropriate model parameters in order to describe the material’s mechanical performance. The first part of the study concentrates on the determination of the physical and mechanical properties of the particles themselves. Relevant hydro-mechanical aspects of the particulate material are investigated. The second part focuses on the mechanical behavior of the aggregates. Using the compaction characteristics and stress ranges prescribed by the product manufacturer, a series of laboratory tests was performed on materials with two different grain-size distributions and water content conditions. The results obtained in the first part contributed to the determination of a phenomenological interpretation of the mechanical behavior of the aggregate. Finally, the quantification of nonlinear stiffness, internal friction angle, and its dependency on normal effective stresses and