Development of innovative strategies for durable bridge design and rehabilitation by use of high and ultra-high performance fibre reinforced concretes

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A large proportion of concrete bridges exposed to severe environmental conditions present significant deterioration. The main phenomena observed on piers, beams and bridge decks are reinforcement corrosion and concrete spalling, which have for consequences the reduction of the load-carrying capacity and the alteration of the durability of infrastructure. Since the 1990's, considerable research has been focused on the development of High and Ultra-High Performance Fibre Reinforced Concretes (HPFRC and UHPFRC). Compared to normal strength concrete, HPFRC and UHPFRC present outstanding improvements in terms of mechanical properties and durability. Therefore, the potential of application of those materials for design and rehabilitation of bridge infrastructure is obvious. Research must be performed to complete the characterisation of HPFRC and UHPFRC, and thus promote their utilisation in infrastructure. The proposed research program is divided in two topics. Topic (1) aims to bring fundamental knowledge on water permeability and self-healing of HPFRC and UHPFRC. The influence of material parameters (fibre content, type and volume of binder) and structural parameters (static and cyclic loadings) will be studied. Topic (2) has for objectives to evaluate the impact of fibre orientation in structures on the FRC size effect and creep under high loads. Thus the onset and the extent of hardening and softening behaviours of HPFRC and UHPFRC will be estimated in various conditions, as well as the contribution of cracking on viscoelasticity. Research topics will combine experimental testing and nonlinear finite element analysis. The proposed research will lead to the optimized utilisation of strain and strength capacities of HPFRC and UHPFRC at serviceability, and to elaborate provisions ensuring an optimal mechanical behaviour and durability of infrastructure. The research program will promote the development of new strategies for design and rehabilitation, reduce maintenance costs and improve the long term performance of bridges. It will involve 1 technician, 1 Ph.D. and 4 M.Sc. students and 7 undergraduate students. Many occasions will be given to HQP to deepen knowledge and acquire new skills within this research program.