The expansive/reactive subgrade issue has been prevalent in pavement construction throughout Australia, with an estimated 30% of the country’s land surface covered by expansive soil. The shrink-swell problem caused by subgrade movement poses a significant challenge, damaging constructed pavements. Various approaches have been implemented to address this issue, mitigate the detrimental effects, and combat the damage caused by expansive soil. A minimum non-reactive or stabilised cover depth is recommended for low to moderately reactive subgrades. However, in the case of highly reactive subgrades, Austroads and state road agencies advise conducting a comprehensive geotechnical assessment to explore alternative solutions. This article evaluates the potential of geogrid and geotextile in resisting movement caused by reactive soil and assesses their effectiveness in minimising pavement damage. Three road sections were constructed using different configurations. One road section utilised only geogrid, another combined geogrid and geotextile, while the control section had no geogrid or geotextile. The geogrid and geotextile were placed over the expansive subgrade. The design traffic, subgrade CBR (California Bearing Ratio), and reactivity index of the subgrade were consistent across all three road sections to evaluate the performance of pavement configurations. Similar road sections were constructed on three different reactive soils in Adelaide. Over a period of time, road performance surveys were conducted following the guidelines provided by Austroads. The findings revealed that both the geogrid section and the geogrid with geotextile section outperformed the control section in all three locations. This indicates that the inclusion of geogrid and geotextile significantly improved the performance and durability of the road sections constructed on reactive soils.
Evaluation of Pavement Performance for Three Different Designs on the Expansive Subgrade: Three Case Studies
Lecture Notes in Civil Engineering
International Conference on Transportation Geotechnics ; 2024 ; Sydney, NSW, Australia November 20, 2024 - November 22, 2024
Proceedings of the 5th International Conference on Transportation Geotechnics (ICTG) 2024, Volume 8 ; Chapter : 2 ; 11-17
2024-10-22
7 pages
Article/Chapter (Book)
Electronic Resource
English
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