MECHANICAL CHARACTERIZATION AND INFLUENCE OF WATER ON WMA BY ADDING SYNTHETIC ZEOLITE

ABSTRACT: The Warm Mix Asphalt (WMA) can be produced through different techniques, including the use of asphalt emulsion, waxes and paraffins, two binder components (soft and hard) and synthetic zeolite. Synthetic zeolite is principally composed of a siliceous structure with large and interconnected spaces, which can accommodate molecules of water. Synthetic zeolite can hold water in its structure at low temperatures and drive it out after heating. From a technical point of view, at mixing temperature, synthetic zeolite gradually releases a small amount of water and, as a consequence of water vapor emission, generates a foaming effect in the bitumen. This process allows to increase the workability of the asphalt mixture or lower mixing and laying temperatures. However, the released water could affect the adhesion between aggregates and bitumen or the cohesion of the mastic.