Utilization of Ultra High Performance Concrete for Offshore Applications.

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The development of Ultra High Performance Fiber Concrete (UHP-FRC) is deemed as one of the most promising technological advances in material applications suitable for structural Engineering. The new material exhibits exceptional mechanical and durability properties. Concepts of particle packing using nanotechnology have been taken one step further to produce it. The enhanced ductility, impact resistance and energy absorption capacity of the new concrete makes it an ideal material for use in high resistance structures. The present research investigation will be focused on studying the concrete plate under static and impact loading. The use of thin plate can be used as a concrete form for thick mega important structures like offshore and nuclear containment structures or it can be attached to building exterior panels to produce safer more sustainable structural shield in the future.***The new material has been used for different parts on the roof, base slab and other parts of the new offshore Hebron gravity concrete platforms. UHP-FRC has an excellent resistance to spalling, scabbing, and fragmentation, making it an ideal material for wave forces and sea ice for the splash zone. The new material is very well used for offshore wind turbine structures applications.***The cracking, tension stiffening and reinforcement ratios of UHP-FRC plate are important design factors for any offshore structure. The impact loading of UHP-FRC plate under dropped weight will be investigated experimentally, analytically and numerically. Four analytical models will be developed based on the critical impact energy for radial cracking, spalling, tunneling (scabbing) and penetration. The Random Decrement (RD) method will be used determine the dynamic properties of the tested plates before and after testing. The natural frequency, damping ratio, normalized RD and normalized deflection will be determined for the tested plates at different nodes. A critical impact energy expressions will be developed after considering the change of the modulus of elasticity due to Dynamic Impact Factor (DIF) for quasi-static domain, and dynamic domain. ***A numerical investigation is being developed using a concrete damage plasticity constitutive mode suitable for large deformation. A series of laboratory tests has been conducted at Ryerson lab under supervision of the applicant to determine the identification model parameters. The damage plasticity model under strain rate dependent is considered as a modification of the Drucker-Prager strength hypothesis. Tensile and  damage parameters will be used for the model. The developed numerical FE model will be used on the simulation of the impact problem using explicit dynamic analysis technique. The long term objective will be focused on the successful development of an efficient design of a thin plate to be used as a shield against impact for important structures. ***********