HP-GPC CHARACTERIZATION OF ASPHALT AND MODIFIED ASPHALTS FROM GULF COUNTRIES AND THEIR RELATION TO PERFORMANCE BASED PROPERTIES

H. l. Abdul Wahhab, Mohammad F Ali. I. M. Asi,

and I. AL- Dubabe

INTRODUCTION

Asphalt producing refineries in the Gulf countries include Ras Tanurra and Riyadh (Saudi Arabia), AL Ahmadi (Kuwait), and BAPCO (Bahrain) Riyadh and Ras Tanura refineries are located in the central and eastern Saudi Arabia respectively. Arabian light crude oil is used to produce 2000 to 3000 tons of asphalt per day using vacuum distillation, air blowing and grade blending techniques to produce 60/70 penetration grade asphalts in each of these two Saudi refineries. All of the asphalt cement used in Saudi Arabia, Qatar, and parts of the United Arab Emirates is supplied by Riyadh and Ras Tanura refineries.

AL-Ahmadi refinery supplies all of the asphalt cement needed for construction in the state of Kuwait Ratwi-Burgan crude oil mix is used to produce 750 to 1000 tons of asphalt per day using vacuum distillation and air blowing processes

BAPCO refinery, Bahrain- utilizes crude oils produced from Saudi oil fields and supplies asphalt cement needed for construction in Bahrain, Oman and parts of United Arab Emirates

The roadway network in Gulf countries has developed more rapidly than in many industrialized countries. The entire roadway network is built using flexible pavements due to the availability of relatively low cost asphalt binders The asphalt binder plays a significant role in pavement ability to withstand thermal and fatigue cracking and contribute to permanent deformation behavior Fatani et al in a study about permanent deformation in Saudi Arabia have concluded that the asphalt cement is responsible for a major part of rutting in the region, and that extreme weather conditions of the Gulf countries has promoted an inferior performance of asphalt concrete rnixes in the field.

Asphalt binders are theremo-visco-elastic materials where temperature and rate of load application has a great influence on their behavior. Asphalt consistency and hence ability to sustain and hold their fundamental cementing mechanism changes depending on temperature The pure asphalt lack the proper balance of viscous fluid-elastic sponge properties which usually occur due to an effective elastic network created by molecular association. In recent years various studies have shown that polymer modification can be successful in forming this viscous fluid-elastic sponge balance by creating molecular entanglement in asphalt.

This study was initiated to evaluate different locally available polymer materials in order to identify potential polymers to modify asphalts to satisfy the performance requirements in the Gulf countries' environmental conditions. The storage stability of the asphalt-polymer blends and the life cycle cost analysis of the polymer modification were also studied

Keywords. Modified Asphalts, HP-GPC Characterization, Gulf Countries Asphalts