Influence of polymer enhancement on water uptake, retention and barrier performance of geosynthetic clay liners

Zhi Chong Lau, Abdelmalek Bouazza, Will P. Gates

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

This paper explores the influence of polymer enhancement on water uptake and retention by geosynthetic clay liners (GCLs) across a wide suction range (up to 106 kPa), including the low suction regime (0.1–10 kPa) typically omitted in past studies. The suction measurement methods used enabled elucidation of water uptake and retention behaviour through the framework of GCL pore structures and their corresponding suction regimes. Polymer enhanced GCLs (PE-GCLs) have high maximum water uptake, and both the water entry and air expulsion values tend to be high. Due to high swelling, the onset of geotextile confinement for PE-GCLs was observed at high suctions. The impact of polymer becomes more apparent when the bentonite achieves a pseudo-two-layer interlayer hydration state at a suction of about 40 MPa (RH = 75%). The hydration mechanism for the polymer fraction in bentonite is unique to the specific polymer type, polymer dosage, and manufacturing process. The water retention behaviour at the low suction range is caused by the in-filling of geotextile pores, bentonite swelling and extrusion, and polymer water adsorption. Insights from this study can form the basis for developing a more suitable bimodal generalised model for fitting the water retention curves of GCLs.

Original languageEnglish
Pages (from-to)590-606
Number of pages17
JournalGeotextiles and Geomembranes
Volume50
Issue number4
DOIs
Publication statusPublished - Aug 2022

Keywords

  • GCLs
  • Geosynthetics
  • Polymers
  • Unsaturated
  • Water retention curves

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