Assessment of asphalt binder grading systems in hot mix asphalt pavements to Sri Lankan conditions

Abstract

Asphalt hinders are typically categorized according to the physical characteristic Traditional grading systems such as penetration and viscosity grading system and the new method. Super pave grading system are available currently. Method used in Sri Lanka is the traditional Penetration grading system which is about 100 years aid. A study relevant to the Sri Lankan conditions based on hinder grade affect on pavement performances, binder property variations and suitable asphalt hinder grades are carried out herein. A road investigation on pavement distresses is carried out to evaluate the pavement performances with the change of climate and the hinder grade used. The asphalt binders used for the road constructions in Sri Lanka are evaluated by analyzing the hinder properties. A questionnaire is conducted to evaluate the current industry practices. The suitable hinder grades for different areas of the country are identified then, according to the climatic conditions especially the Super pave prediction algorithms, used to convert the air temperatures into pavement temperatures are verified to Sri Lankan climatic conditions. The effect of binder grade on pavement distresses is identified through the road investigation Binder property analysis and the questionnaire show that industry does not maintain the standards properly. Also the requirement of different hinder grades for different zones is identified. Moving to a better hinder grading system while maintaining its standards and changing the binger grade with the climatic conditions according to the developed ArcGIS maps is recommended.