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Topic

Experimental evaluation of the wicking and reinforcement functions of wicking nonwoven geotextile-geogrid composite in roads

Department of Civil Engineering

Date & location

• Wednesday, December 4, 2024

• 3:00 P.M.

• Engineering Office Wing

• Room 230

Reviewers

Supervisory Committee

• Dr. Cheng Lin, Department of Civil Engineering, University of Victoria (Supervisor)

• Dr. Min Sun, Department of Civil Engineering, UVic (Member) 

External Examiner

• Dr. Wenbo Zheng, Department of Geotechnical Engineering, University of Northern British Columbia 

Chair of Oral Examination

• Dr. Mara Marin, Department of Political Science, UVic

   

Abstract

Road performance is significantly enhanced by incorporating geosynthetics through their reinforcement and drainage functions. This study introduces a new geosynthetic that integrates all these functions. It is made of biaxial polypropylene geogrids heat-bonded to wicking nonwoven geotextiles (WNWGs). Unlike the wicking woven geotextiles comprising deep-grooved fibers, WNWGs are chemically treated to be hydrophilic and thus possess rapid wetting and wicking properties while preserving the large lateral drainage functionality of conventional nonwoven geotextiles. To assess the wicking behavior of the geotextile, a series of wicking tests were conducted in water alone and saturated soils under controlled temperature and relative humidity. Additionally, contact angle measurements and microscopic analyses with Scanning Electron Microscopy (SEM) were conducted to elucidate the underlying wicking mechanisms. To assess the combined reinforcement and wicking performance of the geocomposite, a series of model tests including rainfall simulation and plate loading tests were performed on the WNWG-geogrid composite reinforced bases over weak subgrade using a customized model test apparatus. The results confirmed that the inclusion of WNWG-geogrid composite significantly enhanced drainage, stiffness, and bearing capacity of road bases. The findings from this study demonstrate the promising performance of this new composite and provides valuable reference for full-scale tests and applications in roads. 

Keywords Geotextile-geogrid composite, wicking nonwoven geotextile, wetting and wicking, rainfall simulation, plate loading test, bearing capacity