Granular base equivalency

Granular base equivalency or granular base equivalence (GBE) is a measure of total pavement thickness.

[1][2] Since pavement is composed of multiple layers with different physical properties, its total thickness is measured by GBE.

GBE translates the thickness of different road layers to a number using a set of coefficients.

In the next step the sum of the converted layer thicknesses is calculated.

[2] This sum is called granular base equivalency, which is a popular and important measure in pavement design and pavement performance modeling.

Profile of pavement showing the different layers of material in a certain road in Ontario. The thickness of these layers can be translated to GBE.