Assessment of Cryogenic Fluid Spill Damage to Concrete

This paper summarizes the investigative effort to determine the extent of damage to the elevated concrete pedestal and pre-cast concrete piles supporting a liquefied natural gas (LNG) storage tank following a leak of the LNG at cryogenic temperatures typically below-160 °C (–260 ° F) and lasting approximately 48 hours. The study consisted of a non-destructive evaluation phase to determine the extent of damaged concrete and a subsequent laboratory testing phase based on concrete cores. Pulse velocity measurements during the non-destructive testing phase indicated the distressed concrete was localized. Cores removed from both unaffected and distressed locations identified during the non-destructive phase were tested in the laboratory phase to determine the Dynamic Young's Modulus of Elasticity and Air Permeability Index on 25 mm (1 inch) thick disks taken from the cores, and compressive strength. Analyzing concrete disks at 25 mm (1 inch) depths provided insight into damage gradients. The Air Permeability Index and Dynamic Young's Modulus of Elasticity measurements of the disks were effective in determining both depth and damage relative to depth as a result of the cryogenic spill. The laboratory studies confirmed that the distressed zone of the concrete was limited to a near-surface zone as suggested by the pulse velocity testing. The structure was returned to service upon completion of the assessment.