Mechanical properties of cement-bound recycled pavements

Tensile (uniaxial and flexural) and compressive (uniaxial cube and equivalent cube) tests were carried out on mixtures of crushed aggregates and milled bituminous materials with proportions by mass 100/0, 75/25, 50/50, 25/75, 0/100, respectively. All mixtures were bound with 3 or 5% by mass (b.m.) cement and 5·2% b.m. water. Strength and modulus of elasticity were determined for one-day- and 60-day-old specimens. It was found that this type of recycled materials forms a generation of new materials with different and enhanced properties in comparison with ordinary cement-bound granular materials. Both strength and modulus of elasticity decreased as the proportion of milled bituminous material in the mix increased. However, the rate of decrease of the tensile strength was lower than that of the corresponding compressive strength and similarly the rate of decrease of the modulus of elasticity was lower than that of the corresponding strength. For each mix proportion a different relationship existed between compressive strength and tensile strength and between tensile strength and the corresponding modulus of elasticity.