A laboratory study on cold-mix, cold-lay emulsion mixtures

This paper describes laboratory experiments and presents results for the performances of cold-mix, cold-lay emulsion mixtures. The main objective of the experiments was to evaluate and improve the properties of the cold mixtures. The mixture properties evaluated were: volumetric properties, indirect tensile stiffness modulus (ITSM), repeated load axial creep and fatigue. These properties were compared with conventional hot asphalt mixtures not containing any waste/recycled materials. To optimise the performances of the mixtures, a target of ITSM value of 2000 MPa was selected. At full curing conditions, the stiffness of the cold mixes was found to be very similar to that of hot mixtures of the same penetration grade base bitumen (100 pen). Test results also show that the addition of 1–2% cement significantly improved the mechanical performance of the mixes and significantly accelerated their strength gain. The fatigue behaviour of the cold mixes that incorporated cement was comparable with that of the hot mixtures.