Abstract

The present paper is an attempt to evaluate the coefficient of hydraulic conductivity of several types of granular materials usually used as base and subbase course materials in pavement construction in Iraq. The selected materials confirmed with S.O.R.B. specifications, (State Organization of Roads and Bridges) issued in Iraq in l986 for granular base and subbase layers. The tests were performed under constant head condition within the range of validity of Darcy’s Law under laminar flow conditions. The regression analysis of the test results revealed an equation that predicts the degree of packing as a function of void ratio and mean particle diameter. The equation can provide quick estimate of the degree of packing which is directly related to the coefficient of hydraulic conductivity of any granular layer