Shear Behavior of Reinforced Geosynthetic Clay Liners Available to Purchase

Ring shear tests were performed to evaluate the effect of bentonite on the interface shear strength between a geomembrane and a reinforced geosynthetic clay liner (GCL), and the internal shear behavior of reinforced GCLs. The tests yielded an interface shear strength that is in agreement with the back-calculated shear strength values from two test pads that deformed at the U.S. Environmental Protection Agency GCL Test Section in Cincinnati, Ohio, USA. The ring shear tests showed that the internal shear strength of reinforced GCLs depends on the following two factors: (i) resistance against reinforcing fiber pull-out and/or tearing; and, (ii) shear strength of bentonite. The laboratory tests indicate that fiber resistance is the predominant internal shear strength factor. Recommendations are presented for the rate of shear that should be used for internal shear testing of reinforced GCLs.