Can we "see" what is happening to other layers of geosynthetics under a geomembrane without removing the geomembrane? This has recently become a significant issue with the finding that in certain circumstances GCL roll overlaps may be reduced and rolls may even separate in service. The answer is "yes" – at least in one circumstance.
During recent tests to evaluate the use of infrared thermography to nondestructively measure geomembrane seam strength, I-CORP took two 200 mm square pieces of GCL and overlapped them by 100 mm. We then placed another piece about 75 mm to the side of the overlapped ones, as shown in Figure 1.
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| Figure 1 |
The GCLs were covered with a 1 mm thick piece of tan-colored PP geomembrane, as shown in Figure 2.
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| Figure 2 |
Without adding any heat, and with the PP not in intimate contact with the GCLs, an infrared thermogram (Figure 3) distinctly showed all three pieces of GCL, the overlap, the gap, and a metal ruler in the gap.
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| Figure 3 |
Will it work with black HDPE geomembrane? See the linked title below for the results.
Please contact Ian Peggs for comments or questions.
Click the title below for Ian Peggs’ report on GCL Under Black Geomembrane.
Title: GCL Under Black Geomembrane
By: Ian Peggs, I-CORP INTERNATIONAL
