Ultra-High-Performance Fibre-Reinforced Concrete for Rehabilitation and Strengthening of Concrete Structures: A Suitability Assessment

Abstract

Ultra-high-performance fibre-reinforced concrete (UHPFRC) is a cementitious composite which contains fibres. UHPFRC has emerged as an effective structural retrofitting material due to its superior mechanical properties. In addition, UHPFRC has outstanding durability, ductility and workability; a low permeability; and a high abrasion and fire resistance. These improved characteristics of UHPFRC are obtained by reducing the content of free water in the concrete matrix (leading to less air voids), introducing high strength ductile steel fibres, replacing coarse aggregates with well graded fine aggregates and introducing highly active pozzolanic materials. UHPFRC has excellent bonding with normal strength concrete and it eliminates the issue of debonding which is common in other retrofitting techniques employing fibre-reinforced polymers or externally bonded steel plates. Therefore, considering various aspects, UHPFRC-based structural retrofitting possesses a number of advantages. This paper presents a review of previous studies employing UHPFRC for structural retrofitting applications, highlighting its advantages, limitations and challenges. Aspects of flexural strengthening, combined axial and flexural strengthening, shear strengthening, impact resistance and torsional strengthening are considered for this review. Altogether, the paper aims to enhance the awareness of UHPFRC for structural retrofitting as a step forward towards effective field applications and to outline the potential future directions of research.

Structural Health Monitoring of Fiber-Reinforced Concrete Prisms with Polyolefin Macro-Fibers Using a Piezoelectric Materials Network under Various Load-Induced Stress

“…Fibers were added directly to the fresh concrete batch in two different proportions: 5 kg/m 3 and 6 kg/m 3 (per 1 m 3 concrete). Special attention was given when adding the fibers to the pan to avoid inhomogeneity of fiber distribution and achieve flowability of the fresh FRC mixture [31,32]. The macrosynthetic fibers were admixed steadily in small quantities while stirring to avoid forming masses of lumps.…”

Retrofitting Shear Critical Beams using Ultra High Performance Fibre Reinforced Concrete (UHPFRC)

“…Further, externally jacketed steel plates are susceptible to corrosion, compromising the load carrying capacity. UHPFRC jacketing can overcome most of the issues in conventional retrofitting techniques [6].…”

“…The retrofitting of structural members with UHPFRC has found widespread application in various aspects, including flexural strengthening, combined axial and flexural strengthening, shear strengthening, torsional strengthening, and enhancement of impact resistance [6]. Previous researchers have explored the retrofitting of various structural members, including beams, columns, slabs, and load-bearing walls, using UHPFRC (e.g., [6,11]). The scope of this study is limited to the rehabilitation of RC beams.…”