Drainage and Mechanical Behavior of Highway Base Materials

Abstract

The mechanical and drainage properties of graded aggregate base (GAB) materials used in mechanistic pavement design are the level one inputs. Several highway agencies need an evaluation of the stiffness and drainage characteristics of GAB stone delivered at highly variable gradations to construction sites. To fulfill the current need, the mechanical and drainage properties of seven GAB materials with varying petrography and physical properties were evaluated in the laboratory and field. The resilient modulus and hydraulic conductivity test results obtained in the laboratory were compared with the field measurements. The summary resilient moduli at optimum moisture content (OMC) were generally lower than those at OMC–2%; however, permanent deformations increased with the addition of moisture content. The correlation between the mean laboratory and field stiffness/modulus values was fair to acceptable (