Effect of polypropylene fibre reinforcement on the consolidation, swell and shrinkage behaviour of lime-blended expansive soil

Abstract

In this article, synthetic fibres in the presence of lime stabilisation are proposed as an alternative to overcome the issues related to shrink-swell distress in expansive soils. Two types of synthetic fibres, Fiber Cast® (FC) and Fiber Mesh® (FM), were studied by conducting one-dimensional fixed ring Oedometer swell-consolidation and bar linear shrinkage tests. Three dosages (0.2, 0.4 and 0.6% by weight of soil) and two lengths of the fibres (6 and 12 mm) were evaluated with and without lime treatments. The results indicated that FC fibres had better swell restricting performance in the absence of lime treatment, while in the presence of lime both fibres had similar performance in reducing swelling. Shrinkage tests results showed that irrespective of dosage levels, both the fibres had pronounced effect in reducing the linear shrinkage strains up on lime treatment. Non-linear best fit equations have been proposed to relate compression index (C _c ) and recompression index (C _r ) of expansive clay deposits with and without lime treatment to amount and dosage of FC and FM reinforcements. The proposed non-linear fit provides a mean for recognising, more efficiently, the patterns in the experimental data and predicting the compression indices, C _c and C _r reliably.

Keywords:

• Expansive soils
• Fibre reinforcement
• Lime
• Swell index
• Compression index
• Void ratio
• Linear shrinkage strain
• Regression analysis

Acknowledgements

The authors would like to thank the reviewers for their constructive comments which helped the cause of the manuscript.