International Journal of ICT-aided Architecture and Civil Engineering Vol.1, No.2 (2014), pp.33-50 http://dx.doi.org/10.14257/ijiace.2014.1.2.03 ISSN: 2383-4773 IJIACE Copyright ⓒ 2014 SERSC Performance Evaluation of Polymer Modified Asphalt Mixtures Eslam Magdy Mohammed Deef-Allah  and Ahmed Mohamady Zagazig University, Faculty of Engineering engeslam1988@yahoo.com Abstract Attention has been increasing towards the use of polymer modified asphalt, because conventional asphalt mixtures cannot resist the high axle loads and tire pressures. Several classes of modified binders have been used in asphalt pavements. The main objective of this research was to evaluate the effect of adding several types of polymers on asphalt cement and asphalt mixtures. Experimental program involved two phases. The first phase was modifying the asphalt using six types of polymers then evaluating the properties of the modified asphalt. The second phase was evaluating the effect of binder modification on Marshall mix design and indirect tensile strength of the asphalt concrete mixtures. It was found that the optimum percentage of PVC, plastic bags and novolac was 4%, and the optimum percentage of HDPE was 5% by weight of asphalt. These percentages caused increase in kinematic viscosity, stability, and indirect tensile strength and caused reduction in penetration. Keywords: Asphalt mixtures; polymers; poly vinyl chloride; novolac; high density polyethylene; waste plastic bags 1. Introduction The increase in road traffic during the last two decades, in addition with an insufficient degree of maintenance, has caused an accelerated deterioration of road structures in many countries [1-7]. The modification of asphalt with polymers is considered one of the best options to improve asphalt properties. Polymers increase considerably the useful temperature range of the binders [2, 3]. The added polymer can strongly enhance the binder properties and permit the building of safer roads and the reduction of maintenance costs by increasing the stiffness of the bitumen and improves its temperature susceptibility [3-7]. Roberts et al. reported that low density polyethylene (LDPE) has been used as an asphalt modifier. The LDPE content was typically 4-6 percent by weight of the modified binder [3]. The addition of LDPE to asphalt cement reduces its penetration, and increases its kinematic viscosity, absolute viscosity and softening point [3]. However, Roberts et al did not show clear results for the effect of LDPE on asphalt binder and mixes. Processed plastic bags (one form of LDPE) were used as an additive with heated bitumen in different proportions [8, 9]. It was observed that the penetration and ductility values of the modified bitumen decreased with the increase in proportion of the plastic additive up to 12% by weight. The softening point of the modified bitumen increased with the addition of plastic additive up to 8%. The optimum percent of plastic bags that gave maximum stability was 8% and above this percent stability decreased [8]. El-saikaly recommended waste plastic bags content of 9.0 % by weight of binder as the optimum content for the improvement of performance of asphalt mix [9].  Corresponding Author