Since the development of ultra-high performance fibre reinforced concrete (UHPFRC) in the late 1990s, the use of this type of concrete has grown significantly. This is due to the superior mechanical and durability characteristics of UHPFRC compared to regular concrete. The Ontario Ministry of Transportation (MTO) utilizes UHPFRC in field-cast joint applications between precast concrete bridge deck panels. MTO has recognized the benefits that could be achieved with the use of UHPFRC including the superior flexural strength that ensures continuity of the precast panels and the good long-term performance due to the extremely low porosity and superior toughness. MTO’s first use of UHPFRC was in 2006, for field cast joints. MTO has tendered the use of UHPFRC in this application for over 120 structures. Every year, nine to fifteen bridges are constructed with UHPFRC field-cast joints. The majority of bridges where UHPFRC has been used by MTO are located in the province’s Northeast and Northwest Regions, where primarily precast concrete is used for bridge construction. Currently, for a UHPFRC product to be used in MTO work, the product must pass the designated sources of materials (DSM) approval criteria and be listed on DSM list 9.25.50. This paper aims to present MTO’s experience with UHPFRC used in field-cast joints. This includes the best practices for material handling and storage, mixing, placing, finishing, curing and surface preparation. The advantages and limitations of the UHPFRC will also be presented based on MTO’s experience. Furthermore, the paper will present the steps that MTO has taken through the pre-approval acceptance criteria, specifications and quality assurance testing to ensure the successful use of UHPFRC in field-cast joints.
Keywords: ultra-high performance fibre reinforced concrete, bridges, flexural strength, durability, field-cast joints, curing.