Determination of stiffness modulus and poisson's ratio of lightly stabilized granular materials from indirect diametral tensile testing

Abstract

Lightly cementitiously stabilized granular materials are generally characterised by their tensile properties that are required for the analysis and design of a pavement structure involving these materials. Tensile properties include tensile strength, stiffness modulus, and Poisson's ratio. However, there are limited studies on the mechanistic determination of stiffness modulus and Poisson's ratio of lightly stabilized materials; rather, a magnitude of Poisson's ratio is often assumed. This paper examines the use of monotonic and cyclic load indirect diametral tensile (IDT) testing to determine the Poisson's ratio and stiffness modulus of lightly stabilized granular materials. The experimental program included the determination of IDT strength, static and dynamic stiffness modulus, and Poisson's ratio for a typical freshly quarried granular base material stabilized by the addition of 0.5 to 3 % cement-flyash and 1.5 to 3 % slag-lime slow-setting binder. A new IDT testing setup to measure both the horizontal and vertical deformations along the diameters of an IDT specimen was developed and the tests were conducted on 28 days cured samples prepared by gyratory compaction. Details of the new IDT testing arrangement with on-sample deformation measurement for performing monotonic and cyclic load testing to obtain reliable data are discussed. This study indicates that the proposed IDT testing setup with on-sample deformation measurement could be used reliably for determining the tensile properties of lightly stabilized granular materials including the Poisson's ratio.