The owner of an eighty story building was concerned that insufficient extended laboratory durability testing information was available for two silicone structural glazing sealants proposed for use on the new building curtain wall. A two phase laboratory testing program was conducted to resolve these concerns.
Phase I involved testing for durometer and weight loss after extended heat aging by ASTM C661 and C792, cyclic movement after extended exposure in a weatherometer by ASTM C719, and adhesion-in-peel after extended water immersion by ASTM C794. Also, the pull-off strength of the organic coating, that the structural sealants were adhered to, was tested by ASTM D4541. Phase II used glazed components of the curtain wall for mock-up testing to destruction, to determine the ultimate strength of the structural silicone sealant joint by ASTM E330.
Phase I testing indicated that the extended laboratory exposures did not result in any detrimental changes to the properties of the sealants. Also, the pull-off strength of the organic coating exceeded the strength of the structural sealants. Phase II testing indicated that the ultimate strengths of the structural sealants exceeded manufacturer's published strengths.