Non-linear Response in Reinforced Concrete related to Cryogenic Conditions

Abstract

A reinforced outer concrete containment tank exposed for liquefied natural gas was the basis for this study. The containment tank was analysed both linearly and non-linearly by use of two different finite element programs; Abaqus and Sestra/ShellDesign. The main goal for this study was to examine whether a given concrete containment tank would fulfil the formal rules and regulations regarding, the residual compressive zone and the crack width limitation, without a thermal corner protection. Non-linear analyses were carried out by use of temperature dependent material properties. The results showed an acceptable residual compressive zone for both the wall and the slab, but the required limit crack width was exceeded by 100 % (0.5 mm). The residual compressive zone will ensure impermeability and the outer containment tank will withstand a major leak event. Abaqus proved itself to be a good tool for non-linear analysis due to a cryogenic condition.The results from Abaqus were compared to a similar model created and analysed with Sestra/ShellDesign. Some unfavourable peak values was found at the edges of the thermal load. The non-linear reinforcement stresses were however reliable for the tests ran without any concrete tensile capacity, and should be considered a solid basis for further studies for Sestra/ ShellDesign due to a cryogenic liquid spill condition.