Test Method Description

The proposed method is designed to simulate shear forces of a magnitude that are typically seen in structurally glazed curtainwall designs including an additional safety factor. This test method uses cured ASTM Cl 135 specimens inserted into a device (shown in Fig. 2) that can impose shear either transversely (as would occur at a head or sill condition) or longitudinally (as would occur at jambs) across the long width of the specimen (see Fig. 3). The direction of shear is dependent upon how the specimens are affixed into the device. Once inserted, they are firmly secured such that when the shearing force is imposed the plates remain parallel.

The device (shown in Fig. 2) consists of a chain-driven adjustable cam powered by a variable speed electric motor. A mechanical counter is fitted on the device to count cycles. The cam in turn causes a floating head assembly to move relative to a fixed head assembly between which the sealant samples are inserted.