Bond Enhancement in Curved Sandwich Shells

As follow-up to recent papers by Marshall et al. (2010, 2012), research on steel-concrete-steel (SCS) sandwich shells for Arctic offshore structures continues at two universities. National University of Singapore is testing heavy transverse reinforcement which ties the outer steel plates together. Lamar University in Texas originally studied the composite ice wall concept in the late 1980s, and is now testing surface treatment with a size-tiered gradation of mini-studs, macro fibers (steel) and micro fibers (synthetic), intended to develop the full bulk properties of the Fiber Reinforced Concrete (FRC) core in radial tension and punching shear. Using ISO’s design non-hydrostatic partial span loading on the Singapore Cone, radial bond stress at the inner steel plate is low and deemed attainable for both the stud enhanced bonding surface and the bulk concrete core. The steel shell serves as prefabricated permanent formwork, and the arched vaults resist external ice loading mainly by compression, provided the sandwich does not disintegrate in an unstable fashion.