A new standard for determining the peel strength of GCCM materials is needed because: i.the current tensile strength test methods do not deal effectively with multiple layer composite materials, and ii.the product is both a supple textile-like material when uncured, then when hardened, it becomes a thin shell-like hard structure. The method of clamping/positioning GCCMs is different compared with current methods, because rather than bending the top and bottom layers so they are clamped perpendicular (90 degrees) to the GCL specimen, back plates are used so a GCCM layer is peeled back parallel (i.e. at 180 degrees) to the specimen. GCCM peel strength should be tested in both uncured and cured states, to include peeling the top layer and individual bottom layers. There are potentially 9 different peel tests of the different components on GCCMs. Finally, for some GCCMs a peel failure occurs as a series of peaks and troughs so calculating mean peel strength alone may not provide sufficient information to understand the peel failure. Reporting a peak force would help understand the load required to tear the connecting fibers. Mean or average peel failure force should also be reported.
The title and scope are in draft form and are under development within this ASTM Committee.