Characterization of Cementitiously Stabilized Granular Materials for Pavement Design Using Unconfined Compression and IDT Testings with Internal Displacement Measurements

Abstract

This paper presents the findings of a laboratory investigation on the characterization of a freshly quarried granular base material lightly stabilized with slag-lime cementitious binder involving unconfined compression (UC) testing and indirect diametrical tensile (IDT) testing, both with internal displacement measurements. The UC test investigation involved the determination of the unconfined compressive strength (UCS) and four different types of stiffness moduli from both internal and external displacement measurements. The IDT testing included the determination of IDT strength as well as the static and dynamic stiffness moduli (i.e., SSM and DSM) of the lightly stabilized granular base material from monotonic and cyclic load IDT testing. This study indicates that the stiffness moduli of a lightly cementitiously stabilized granular base material can be determined consistently from UC testing by measuring the deformations internally, and the modulus is more reliably defined as either the tangent modulus at half the ultimate stress or secant modulus at 0.02% strain. The UC stiffness modulus could be estimated reliably from the corresponding UCS value using the regression relationships established from this study. The IDT strength was determined to be equal to 0.1143 times the UCS value and this conforms to the recommendation given in design guides such as AUSTROADS. Moreover, the IDT, DSM, and SSM of a lightly cementitiously stabilized granular base material could be estimated from the UCS of the same material using the correlations developed in this paper which could be used in pavement design.