A high performance fibre reinforced cement based plaster for retrofitting RC members

• Published in: Materials and structures Vol. 46; no. 1-2; pp. 277 - 288
• Main Authors: Hajipour, A., Maheri, Mahmoud R.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2013; Springer; Springer Nature B.V
• Subjects: Applied sciences; Building construction; Building Materials; Building structure; Buildings. Public works; Civil Engineering; Concretes; Concretes. Mortars. Grouts; Construction (buildings and works); Ductility; Durability. Pathology. Repairing. Maintenance; Engineering; Exact sciences and technology; Machines; Manufacturing; Materials; Materials Science; Original Article; Other special applications (sand concrete, roller compacted concrete, heavy concrete, architectural concrete, etc.); Plasters; Processes; Reinforced concrete; Reinforced concrete structure; Reinforcing steels; Repair (reinforcement, strenthening); Retrofitting; Sand; Solid Mechanics; Tensile strength; Theoretical and Applied Mechanics; Plaster; Steel fibres; Fibre reinforced concrete; High strength concrete; Retrofitting; Concrete members; Performance evaluation; Construction materials; Concrete mix design; Compression test; Composite material; Mechanical test; Fiber reinforced concrete; Concrete construction; Steel fiber; Fibre reinforced plastics; Rehabilitation
• ISSN: 1359-5997; 1871-6873
• DOI: 10.1617/s11527-012-9901-7

A high performance fibre-reinforced cementitious composite (HPFRCC) material is developed to be used for retrofitting reinforced concrete members. It can be applied to the face of a concrete member to the desired thickness as a wet mix or as an adhesively-bonded prefabricated slab or strip. The material is compatible with concrete and possesses favourable strength and ductility properties, desirable for seismic retrofit. It overcomes some of the problems associated with the current techniques based on externally bonded steel plates and fibre-reinforced polymer (FRP) laminates caused mainly by the mismatch of their tensile strength and stiffness with that of the concrete member being retrofitted. An extensive rheological analysis is undertaken to develop the appropriate mixes using different types and mix proportions of constituent materials including; fine steel fibres, fine quartz sand, silica fume, cement and superplasticizer. Much reduced amounts of steel fibres are used compared to the previous studies so that ordinary mixing procedures could be applied and a more cost-effective retrofitting material could be developed. Samples made of the optimum mixes are shown to posses very high compressive and tensile strengths and sufficient ductility for the composite plaster to be used externally for strengthening and seismic retrofitting of concrete members.