Performance evaluation of encapsulated road pavement on difficult ground condition

This project focuses on a critical investigation into a novel development of the road subgrade incorporating a pre-hydrated geosynthetic clay liner (RGCL) within a proposed new Encapsulated Road Pavement (ERPS) design system for a Malaysian difficult ground condition. It studied the effect of static loading on different reinforced full scale road pavement model for six (6) months duration. Continuous full scale testing was conducted at Research Centre for Soft Soil (RECESS Malaysia) located in the campus site of Kolej Universiti Teknologi Tun Hussein Onn (KUiTTIIO). The test area consists of very soft clay to a depth of 20 meters (JKR Malaysia, 1987). The new RGCL is expected to act as a barrier that will encapsulate or 'wrap' the imported subgrade layer in order to protect it from the high water table that exists in most parts of the southern region of Malaysia (the state of Johor). Apart from acting as a barrier to the existing sub-surface / ground water present at the test site, the RGCL will also function as reinforcement in the road pavement system. The design and application of RGCL is expected to reduce settlement and the effect of abrupt structural failure to road pavement constructed on soft soil due to traff"ic loadings. It should enhance the performance and prolongs the design life of the road pavement. Laboratory tests on the soil properties and characteristics obtained from the test site were conducted prior to the full-scale trial road embankment construction. Comparisons of different design standards mainly the British and Malaysian Standards were made to understand the current practiced rural road design concept. Full-scale trial road embankments were instrumented with the state of the art monitoring facilities purchased from Canada through fundamental research grants (Chapter 5: Field Instrumentation for full scale research). From this project, it may be concluded that rural roads when constructed on soft clay with high water table, need to be reinforced and encapsulated with an impermeable layer so that the subgrade layer may last longer as its intended design life. Water table and rainfall intensity have an influence on road performance constructed on soft soil. It was also found that the ERPS design system performs better or similar to the road when compared to the unreinforced (Control Section) and geotextile-reinforced (Existing Practice) road pavement respectively. However, further research such as long term monitoring of this research project is recommended so that more concrete conclusion on the behaviour and performance of encapsulated road pavement can be derived. This project contributes in producing reliable, quality rural road pavement design and construction on Malaysian soft soil. This will enable its inclusion into current standards and assist in the construction of better and efficient rural road networks whilst gearing the nation towards achieving the Malaysian Vision 2020.EThOS - Electronic Theses Online ServiceGBUnited Kingdo