Rehabilitation and Strengthening of Concrete Structures Using Ultra-High Performance Fibre Reinforced Concrete

Abstract

An original concept is presented for the durable rehabilitation and strengthening of concrete structures. The main idea is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) complemented with steel reinforcing bars to "harden" and strengthen those zones of the structure that are exposed to severe environmental influences and high mechanical loading. This concept combines efficiently protection and resistance properties of UHPFRC and significantly improves the structural performance of the rehabilitated concrete structure in terms of durability. The concept has been validated by means of field applications demonstrating that the technology of UHPFRC is mature for cast in-situ and prefabrication using standard equipment for concrete manufacturing. This novel technology is a step forward towards more sustainable structures.This keynote paper presents an original concept for the rehabilitation and strengthening of concrete structures. The concept is described and some scientific background regarding the structural behaviour of RC elements strengthened with UHPFRC is given. Finally, this novel technology is validated by means of applications. This paper summarizes more than 12 years of intensive research and development of a novel technology to improve concrete structures.

Strengthening of reinforced concrete beams using ultra high performance fibre reinforced concrete (UHPFRC)

“…7 was adopted for a characteristic size equal to 2mm [31]. This model is in agreement with the model proposed by Habel et al [27] and adopted by Bruhwiler [26] and Noshiravani and Bruhwiler [28]. According to this model, the behaviour of UHPFRC is modelled with an elastic behaviour up to initiation of the microcracking followed by a second linear part in to the phase of strain hardening with multiple microcracking.…”

“…In practise, UHPFRC could be used following the same procedure with the one used for RC jackets. The application of UHPFRC could be done using formworks by adapting the rheological properties of UHPFRC [26]. This novel technique has a great potential for the structural upgrade of the existing structures.…”

“…The findings presented in the previous studies are mostly focused on the mechanical properties of UHPFRC, and there are other published studies on strengthening applications [24][25][26][27][28][29][30][31]. Farhat et al [24] examined beams strengthened with UHPFRC strips.…”

“…In this study [24], UHPFRC prevented shear failure of the beams and the failure load was increased up to 86%. Bruhwiller & Denarie [25] and Brühwiler [26] studied the application of UHPFRC for the rehabilitation of crash barrier wall of highway bridge, bridge pier, and industrial floors, and the efficiency of this method for cast in-situ and prefabrication, using standard equipment for concrete manufacturing, was highlighted. The application of UHPFRC for the repair and strengthening of beam-column joints was investigated by Beschi et al [29] and remarkable bearing capacity increment was observed [29].…”

Strength and Behavior of Bolted Ultra-High Performance Concrete Panel Joint with Geometric Parameter

“…UHPC can be a reasonable alternative to the freeform facade, because it has outstanding mechanical performance, self-compacting property and durability [1,2]. Although the material cost of UHPC itself is much higher than that of normal concrete [2,3], the UHPC facade manufactured by precast method can be assembled by bolt fastening, so the construction cost can be reduced and the whole construction cost can be reduced.…”