Influence of polymers on the properties of asphalt concrete paving materials

Abstract EN

Additives are usually suggested in asphalt concrete paving mixtures wherever extra performance and durability are desired.

Polymer modification, using solutions lolls using either elastomer's elastomer's, seems to be among the best solution to improve asphalt mixture properties.

The objective of this research program is to identify through laboratory testing the most promising polymer type and content for the reduction of permanent deformation at high temperature (higher stiffness) and the provision of more resistance to thermal cracking at low temperature (higher tensile strength), using locally available materials.

A selected gradation of aggregate and mineral filler within the specification requirement of asphalt concrete wearing course, together with a (50-60) penetration graded Baoji asphalt cement, and three types of polymers including polyvinyl chloride, polyethylene (plastomers) and rubber (elastomer), at different contents have been used for this purpose.

The desired polymer content by weight of optimum asphalt has been determined to be equal to 0.1 % for polyvinyl chloride, 5.0 % for polyethylene and 2.0 % for rubber.

The use of polyethylene plastomer showed the highest increase in mixture stiffness modulus with an improved resistance to permanent deformation or distortion at high temperature.

The rubber, through the creation of an elastomeric lattice in the asphalt binder, provided the highest tensile strength with all improved resistance to thermal cracking at relatively low temperature.