This paper presents the preliminary results of an experimental program that consists of testing of concrete mixtures with varying water-to-binder ratios (w/b) and cementitious contents. The purpose of this laboratory study is to investigate the minimum cement content that can be used in rigid pavements without sacrificing the performance (i.e., strength and durability). Initially, 16 mixes using only portland cement and 48 mixes incorporating supplementary cementitious materials, namely class F fly ash, class C fly ash and slag as portland cement replacement at levels of 20%, 20% and 40%, respectively, were planned. This paper reports the results of a subset of this study. Concrete mixtures with w/b ranging from 0.43 to 0.65 and cementitious content ranging from 400 lb/yd³ to 700 lb/yd³ were designed. Compressive strength, chloride penetration and air permeability were determined. The findings of the study with the available data are as follows: strength is a function of w/b and independent of the binder content; air permeability increases as w/b and binder content increase; among all the mixtures containing different type and amount of cementitious materials, slag cement provides the lowest 28 day chloride penetration whereas class C fly ash results in the highest chloride penetration.