Exploitation of Ultrahigh‐Performance Fibre‐Reinforced Concrete for the Strengthening of Concrete Structural Members

Abstract

e repair and strengthening of reinforced concrete members are very important due to several factors, including unexpected increases in load levels and/or the damaging impact of aggressive environmental conditions on structural concrete members. Many researchers have turned to using materials for the repair and strengthening of damaged structures or the construction of new concrete structural members. Ultrahigh-performance fibre-reinforced concrete (UHPFRC), characterized by superior structural and durability performance in aggressive environmental conditions, is one of the materials that have been considered for the repair and strengthening of concrete structural members. e repair or strengthening of concrete structures using UHPFRC needs a thorough knowledge of the behaviour of both the strengthening material and the strengthened concrete structure at service load conditions, in addition to an understanding of the design guidelines governing the use of such materials for effective repair and strengthening. In this study, the recent issues and findings regarding the use of UHPFRC as a repair or strengthening material for concrete structural members are reviewed, analysed, and discussed. In addition, recommendations were made concerning areas where future attention and research on the use of UHPFRC as a strengthening material needs to be focused if the material is to be applied in practice.

Repair of Severely Damaged Reinforced Concrete Beams with High-Strength Cementitious Grout

“…A photo of the damaged beam after cleaning is shown in Figure 3 a . Note that the surfaces could be roughened through sandblasting which proved to be a viable solution when applying it to the parent concrete surface before strengthening ( 6 ).…”

“…In all cases, results showed that the strengthening/repair methods lead to higher stiffness, increased capacity, and delayed crack formation and propagation. A literature review of research studies and practical applications on the repair and strengthening of concrete members using high-strength and high-performance concretes is reported by Al Osta ( 6 ).…”

Repair of Heavily Damaged RC Beams Failing in Shear Using U-Shaped Mortar Jackets

“…The aforementioned literature review reveals that the majority of the conducted research is focused on the application of nonconventional jackets in strengthening methods of original RC structural members [17][18][19]21,22,24,[26][27][28][30][31][32][33][34]36,[38][39][40][41][42][43][44][45][48][49][50]56]. Significantly fewer studies investigate such jackets for the repair of preloaded and slightly damaged RC specimens [20,23,25,29,35,37,46,47,[51][52][53][54][55].…”

“…These reasons have led researchers to switch to new jacketing techniques with alternative materials such as steel [17][18][19], advanced materials such as fiber reinforced polymer (FRP) [20][21][22][23][24][25], textile reinforced concrete or mortar [26][27][28][29] and shape memory alloys [30][31][32], cement-based materials such as ferrocement [33][34][35][36], steel fibrous concrete or mortar [37][38][39][40], high-performance fiber reinforced concrete [41][42][43][44][45][46][47][48], self-compacting concrete (SCC) [49][50][51][52][53][54], and thin slightly reinforced flowable mortar [55,56]. Many of these jacketing techniques have been proved successful substitutes to common RC jacketing.…”

Fluid transport properties of normal concrete substrate and a new green fiber reinforced concrete overlay composite

“…This type of concrete is chosen because it exhibits high strength and durability minimizing the need for future maintenance . Al‐Osta and Brühwiler and Denarié reported that UHPFRC has a compressive strength of more than 170 MPa, a flexural strength higher than 30 MPa, and a tensile strength over 8 MPa. Its strength is superior to that of the existing conventional concrete making it a perfect choice to be used as a repair material.…”