Performances of geotextile stabilized unpaved road systems subjected to pretensioning

Abstract

To mobilize sufficient reinforcement contribution in the geotextiles, large deformation must occur at the subgrade level but this may compromise the serviceability state of the unpaved road. Pretensioning of geotextiles was found to be very effective in enhancing the reinforcement potential of the geotextiles without this excessive deformation. This paper will report the findings from laboratory tracking tests and the application of pretensioning method in the field. Six types of geotextiles (nonwoven, woven and composite were evaluated. The benefits of pretensioning were evaluated by comparing the rutting behaviour of the pre-tensioned systems over the control test systems that has no geotextiles. Pretensioningstrain for some geotextiles was also varied to investigate the benefits of pretensioning under different pretensioning strains. It was concluded that the amount of rutting improvement due to pretensioning is a function of geotextiles type and tensile modulus, survivability of geotextiles and the pretensioning strain ratio (ε PT/ε ULT)- The pretensioning method was successfully implemented in an actual field project in Singapore, demonstrating the feasibility of this method.