Re-use of Marginal Aggregates in Cement Bound Mixtures for Pavement Foundations

The paper reports the results of an experimental study aimed at designing cement bound granular mixtures for pavement foundations, made exclusively with marginal materials, namely electric arc furnace steel slags, ladle furnace slags, waste foundry sands, glass wastes and coal ashes, used with different proportions. The laboratory investigation has been divided in a preliminary study of physical-geotechnical properties of the by-products, and in the following mechanical characterization of the cement bound mixtures. The formulation of the mixes has been developed in terms of Proctor, compression and indirect tensile strength tests. At the end of the study, the elastic modulus of the mixtures has been determined by means of ultrasonic tests, at different curing periods. The satisfactory results (compression and indirect tensile strength at 7 days up to 7.33 MPa and 0.74 MPa respectively, depending on the mixtures type), have met the main Italian Contract Specifications, so demonstrating the possibility of using industrial by-products as integral substitutes of the natural aggregates in the production of cement bound granular materials for pavement foundations.