Impact of glass fibre on hydromechanical behaviour of compacted sand-bentonite mixture for landfill application

Desiccation-induced moisture variations creates shrinkage cracks to the landfill liner and can increase the migration of leachates. In addition to this, if the strength of the material is not enough then the effective operation of the liner system may be threatened. Glass fibre can be used to reduce the shrinkage crack of a sand-bentonite mixture. However, addition of glass fibre may adversely affect the other geotechnical parameters of the mixture. Therefore, the main objective of this study is to investigate the effect on geotechnical properties of sand-bentonite mixture due to the inclusion of the glass fibre. In this purpose, tests were performed on sand and bentonite mixture (mixed in a proportion of 90:10) and added with 0.5%, 1% and 1.5% of glass fibre. Test results suggested that compression index decreased; whereas a maximum increase in the swelling index occurred due to the inclusion of 1% of glass fibre. Hydraulic conductivity and rate of consolidation slightly altered with the inclusion of glass fibre to the mixture; whereas peak and residual strength increased. Unconfined compressive strength (UCS) test result suggested that improvement factor, displacement ratio and normalized energy absorption capacity increased with the inclusion of glass fibre.

Automated summary

The inclusion of glass fibre can reduce shrinkage cracks in sand-bentonite mixture but may have adverse effects on other parameters; addition of 1% glass fibre led to the maximum increase in the swelling index; hydraulic conductivity and consolidation rate slightly altered with glass fibre inclusion, resulting in increased peak and residual strength.