Browsing by Author "Mihirani, GS"

Now showing 1 - 3 of 3

item: Conference-Extended-Abstract
Assessment of asphalt binder grading systems in hot mix asphalt pavements to Sri Lankan conditions
(2010) Mihirani, GS; Binduhewa, BWP; Lalithya, GDD; Mampearachchi, WK
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.
item: Article-Abstract
Review of asphalt binder grading systems for hot mix asphalt pavements in Sri Lanka
Mampearachchi, WK; Mihirani, GS; Binduhewa, BWP; Lalithya, GDD
There are three main asphalt binder classification systems; penetration, viscosity and Superpave. The penetration grade 60 –70 binder is used for road constructions in Sri Lanka. The objective of this study was to review the existing asphalt binder grading systems and find the most suitable grading system for Sri Lanka. Performance of the road sections constructed with different penetration grade binders were examined and it revealed that the binder grade significantly affects the performance. A survey was conducted among the professionals involved in the road construction industry to evaluate the current practices. Laboratory test results of the University of Moratuwa and test reports collected from road contractors and the Research and Development (R&D) Division of the Road Development Authority (RDA) were investigated. The test results revealed that binders used in the industry are highly temperature susceptible, though the binder has complied with the standards. Data collected from the Meteorological Department for the last 20 year period were analyzed to estimate the maximum and minimum pavement temperatures, which are required for Superpave binder grading. An algorithm validated for Sri Lankan conditions was used to estimate the pavement temperature from ambient temperature. The requirement of different binder grades for different zones has been identified and a GIS map was developed to select the suitable binder grades for specific road sections in Sri Lanka. PG 58-16 can be recommended for majority of roads while PG 52-10 can be recommended for the regions in the central hilly area of the country where low temperature prevails. Similarly, AC 30 and AC 20 can be specified for high and low temperature zones, respectively. Keywords: Asphalt, binder
item: Conference-Abstract
Review of grading systems for asphalt binders in hot mix asphalt pavements
(Department of Civil Engineering, University of Moratuwa., 2010) Mihirani, GS; Binduhewa, BWP; Lalithya, GDD; Mampearachchi, WK; Pasindu, HR
Asphalt binders are typically categorized by one or more grading systems according to the physical characteristics. Traditional grading systems such as penetration and viscosity grading system and the new method, Superpave grading system are available currently. While some developed countries are using the latest Superpave grading system, most of the other countries are still rely on the empirical Penetration grading system. Sri Lanka also has not moved even to the Viscosity grading system. Some developed countries such as USA, UK are conducting many researches under those areas. India has developed their own grading system to comply with their climatic conditions as well as its location. A study relevant to the Sri Lankan conditions based on pavement performances, currently using grading system and binder grades, the suitable binder grades will be carried out herein. A road investigation on pavement distresses is carried out to evaluate the pavement performances with the change of climate and the binder grade used. Current practice in the industry when dealing with asphalt binder including the property variations, temperature susceptibility, testing methods, etc is evaluated with the test reports collected from the industry and a survey conducted. The suitable binder grades for different areas of the country are identified then, according to the climatic conditions especially the Superpave prediction algorithms, used to convert the air temperatures into pavement temperatures are verified to Sri Lankan climatic conditions. The research identified that binder grade using for the construction make a significant effect on pavement distresses. Even though the literature, reviews that the Superpave grading system is most suitable, Sri Lanka has many restrictions to move even to the Viscosity grading system. The research clearly shows that industry do not maintain even the current using Penetration Grading system. From the analysis of binder grades for different areas, the requirement of different binder grades for different zones are identified. Moving to a better binder grading system while maintaining its standards and changing the binger grade with the climatic conditions as identified is recommended here in.