A new generation of composites materials made of steel tapes in lieu of carbon or glass fiber sheets has recently emerged in the civil engineering field for the seismic upgrade of RC members. The steel tape consists of high tensile strength steel cords made by twisting steel wires within a micro-fine brass or galvanized coating; it can be in situ applied via wet lay-up by using polymeric or inorganic matrices, thus obtaining strengthening systems which can be gathered within the FRP (“Fiber Reinforced Polymer”) and FRCM (“Fabric Reinforced Cementitious Matrix”) families, respectively. This study investigates the feasibility of steel FRP/FRCM systems in improving the seismic performance of exterior RC beam-column joints. An experimental program was organized which includes fifteen beam-column subassemblies with inadequate seismic details. Thirteen specimens were strengthened by using different layouts while the remaining ones were used as benchmarks; once damaged, some specimens were also re-tested after being repaired and retrofitted with steel FRP/FRCM. Test results have provided useful information on the adopted strengthening systems in terms of failure mode, strength and deformation capacity. The performances were also compared with a preliminary numerical model developed within OpenSees framework.
Cyclic Response of R/C Beam-Column Joints Strengthened with Steel FRP/FRCM Composite Materials
DE VITA, ALESSANDRO;FAELLA, Ciro;NAPOLI, ANNALISA;REALFONZO, Roberto
2017
Abstract
A new generation of composites materials made of steel tapes in lieu of carbon or glass fiber sheets has recently emerged in the civil engineering field for the seismic upgrade of RC members. The steel tape consists of high tensile strength steel cords made by twisting steel wires within a micro-fine brass or galvanized coating; it can be in situ applied via wet lay-up by using polymeric or inorganic matrices, thus obtaining strengthening systems which can be gathered within the FRP (“Fiber Reinforced Polymer”) and FRCM (“Fabric Reinforced Cementitious Matrix”) families, respectively. This study investigates the feasibility of steel FRP/FRCM systems in improving the seismic performance of exterior RC beam-column joints. An experimental program was organized which includes fifteen beam-column subassemblies with inadequate seismic details. Thirteen specimens were strengthened by using different layouts while the remaining ones were used as benchmarks; once damaged, some specimens were also re-tested after being repaired and retrofitted with steel FRP/FRCM. Test results have provided useful information on the adopted strengthening systems in terms of failure mode, strength and deformation capacity. The performances were also compared with a preliminary numerical model developed within OpenSees framework.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
