01333042

Component

In many developing countries, where resources are at premium, thin asphalt layer or chip seals are widely used to provide a durable all weather pavement surfacing. In such pavements the role of granular layers is very important in the general performance of the structure. Pavement designs in these countries are empirical in nature and rely on simple input parameters like california bearing ratio (CBR) values. Although widely applicable the traditional CBR test does not provide the mechanical behaviors such as resilient and permanent deformation characteristics of granular road materials. This paper documents the characterization technique developed based on CBR test using repeated load cycles to determine the mechanical behavior of granular (sub-) base materials. The confining pressure developed in the complex CBR stress state is estimated using Strain Gauges. Finite Element analysis has been attempted to model the Repeated Load CBR and derive an equivalent resilient modulus. Furthermore, a large scale cyclic load triaxial test was carried out on coarse unbound granular materials to validate the result of the repeated load CBR. The repeated load CBR test reasonably estimates the resilient modulus of unbound granular materials which can be used as an input in mechanistic pavement design analysis in the absence of triaxial testing facilities.

01329018

11-0407

English

17p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures; Photos; References (19)

California bearing ratio; Chip seals; Deformation; Granular materials; Mechanical analysis; Mechanics; Pavement design; Repeated loads; Strain gages

Unbound granular materials

Highways; Materials; Pavements; I33: Other Materials used in Pavement Layers

Transportation Research Board Annual Meeting 2011 Paper #11-0407

PRP, TRIS, TRB

Feb 17 2011 5:25PM