Author/Authors :
ahmed, manal abd alla zagazig university - faculty of engineering - construction engineering utilities dept., Egypt , zaky, magdy t. research institute (epri) - department refining of egyptian petroleum, Egypt , hassanin, hassan d. zagazig university - faculty of engineering, Egypt , alnahas, ahmed m. zagazig university - faculty of engineering, Egypt
Abstract :
Warm mix asphalt (WMA) is refered to the mix which is produced at temperature 15° c to 60° c lower than typical hot mix asphalt. There are three WMA technologies are in use, Organic Additives, Chemical Additives, and Water Foaming Processes. Warm mix asphalt has been gaining increasing popularity in recent years due to the potential cost savings from reduced fuel at the plant so have attracted interest because of improving workability of mixture and improving air quality. In general, this technology not only reduce paving costs, but also extend the paving season, improve asphalt compaction, allow asphalt mix to be hauled longer distances, and improve working conditions by reducing exposure to fuel emissions, fumes, and heat. The main study objective was to evaluate WMA which are produced using three by-product waxes which are two different characteristics microcrystalline waxes (microcrystalline-1, microcrystalline-2), and paraffin waxes. The effect of these additives on asphalt binder properties as well as the properties of its mixtures produced at 100°c and 120°c were studied these properties were measured using, Rotational Viscometer Test, Penetration Test, of asphalt material, were Marshall Test, Indirect Tensile Strength Test, and Unconfined Compressive Strength Test, are used for mixtures. Analysis of the results showed decreasing in the viscosity with the increase of additives percent, but it still within Egyptian specification of Hot Mix Asphalt (HMA) (more than 320), at 100°c and 120°c for the three additives. Penetration increases with the increasing of additives percent but still within the HMA specification till 5% addition. Mix properties including Marshal Stability and Flow, air voids ratio, showed the addition microcrystalline-1 wax, microcrystalline-2 wax satisfactory outcome for carrying heavy traffic, according to the Egyptian Code and while paraffin wax has been satisfactory results in only light traffic. Indirect tensile strength was increased by increasing percentages of additives because the additives improve the adhesion property of the bitumen to aggregate. Unconfined Compressive strength was varied by increasing percentages of additives with the conventional mixture Therefore, the results split into some results were bigger in permanent deformation and other were smaller in permanent deformation than the conventional mixture.
