Short Term Performance of Bituminous Geomembranes with Respect to Temperature Variations
Date
2023-10-17
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0005-5211-0433
Type
Thesis
Degree Level
Masters
Abstract
There is a significant lack of independentunbiased, peer-reviewed research on the performance of bituminous geomembranes in barrier system applications when compared to the standard barrier polymers used in industry today. The purpose of the research presented in this thesis is to help form a foundation of objective data on BGMbituminous geomembranes (BGMs)s performance in the field, as well as to compare it to polymer barriers like high density polyethylene (HDPE)HDPE geomembranes, LLDPElinear low density (LLDPE) geomembranes, and other well known material types. In addition, in Saskatchewan, the temperature can vary by more than 60°C so a variety of climate conditions need to be considered when installing geomembrane covers. Due to temperature variability, the influence on temperature on the performance of bituminous geomembranes is one of the main variables considered in this research.
A variety of different testing methods were evaluated during this research including multiple ASTM standards for geomembrane puncture and tearing, and short-term performance testing; all with variations in temperature included in the testing procedures. The ASTM style testing methods used the ASTM designated apparatus, while the short-term performance testing was performed using equipment designed and manufactured in the College of Engineering Shops.
When evaluating the puncture resistances of both BGMs and HDPE geomembranes, it was found that as temperatures increase, the displacement required to cause puncture also increasesthere was a positive correlation between the ambient temperature and the amount of displacement that occurs prior to puncture. In contrast to this, the puncture resistance of the samples themselves decrease as temperatures increase, while there was a negative correlation between the puncture resistance of the samples and the ambient temperature. During the sub-zero experiments, it was observed that the stiffness of the geomembranes increased. Additionally, while HDPE geomembranes showed higher overall loads at the time of puncture, the BGMs deformed in much more elastic manners allowing them to reform into their original shape due to the viscosityductility of the bitumen binding, which could be highly beneficial in application.
When looking at the short-term performance of BGMs, in applications with the presence of aggressive over liners with the potential to cause puncture, it was found that both the ES2 and ES4BGM samplesproducts were able to withstand applied stresses of up to 400 kPa without any holes being caused in the barrier. Additionally, at lower temperatures there was little to no surface deformation present on the samples, with very minimal damage from the aggressive over liner.
Based on the findings of this research, it was observed that HDPE retains a higher resistance to puncture than BGMs, however the highly viscous nature of BGMs shows that it could have many advantages in short-term performance depending on the conditions in which it is used.
Description
Keywords
geomembranes, bituminous geomembranes, temperature, performance, durability, bitumen, bgm
Citation
Degree
Master of Science (M.Sc.)
Department
Civil and Geological Engineering
Program
Civil Engineering