Geosynthetic clay liners(GCLs) are an established product group in the geosynthetics industry for various sealing applications. They can be used in slope applications, such as in landfill caps, covers or base sealing systems, effluent and sludge lagoons, where needlpunching or continuous internal reinforcement of the bentonite is required. The needlepunching of GCLs has resulted in internal shear angles of 45°and higher. It is recognized that the needlpunching influences the internal shear stress. A peel bonding test method based on the strip width tensile strength method and the grab test method was developed by GCL manufacturers. Meanwhile the ASTM taskgroup D35.04 is developing a standardized peel bonding test method. Recently a shear tensile test has been introduced as a new test method to measure the bonding strength of needlepunched GCLs. These two manufacturing quality control(MQC) tests, the existing peel test and the newly introduced shear tensile test are compared with each other.(C) 2000 Elsevier Science Ltd. All rights reserved.