Flexural properties of cemented granular materials for pavement design

Abstract

Cementation stabilization of unbound granular materials often offers a feasible solution for the strengthening of existing degraded unbound pavements. The primary determination mode of cemented pavement materials is fatigue cracking. Flexural properties including flexural modulus and tensile strain at break are incorporated into the fatigue criteria of cemented materials. However, there are no universally accepted testing protocols available for cemented pavement materials to determine the aforementioned properties in the laboratory. The four-point bending test is chosen in this paper to study the flexural properties of two different cemented pavement materials as it more closely simulates the stress/strain gradients generated in service. The results from this study revealed that, the strain at break could not be determined with sufficient precision as the tensile strain at the bottom of the specimen just prior to the point of fracture increases uncontrollably without further increase in tensile stress. Based on the response of cemented materials to different loading conditions, an equation is tentatively proposed for determination of the modulus for pavement design.