4This paper investigates the seismic behavior of three full-scale exteriorreinforced concrete (RC)beam-5 column jointsrehabilitated and strengthened with externally bonded Carbon Fiber Polymers(CFRP).The 6 specimens had inadequate detailingin the corezoneandreplicatedjointsof areal substandard building tested 7 as part of the EU-funded project BANDIT.Seven tests were performed in two successive phases. Thebare 8 jointswere first subjected to reversed cyclic loadingteststo assesstheir basic seismic performance. Asthese 9 initial testsproduced severe damagein thecore, the damaged concretewasreplacedwith newhigh-strength 10 concrete. The specimens were subsequently strengthened withCFRP sheets and thecyclictests were 11 repeated. The results indicatethat thecore replacement with new concrete enhancedthe shearstrengthof the 12 substandardjoints by up to 44%over the barecounterparts.ASCE/SEI 41-06 guidelines predict accurately 13 the shear strength of the bare and rehabilitated joints. The CFRP strengtheningenhanced further the joint 14 strength by up to 69%, achieving a shear strength comparable to that of joints designed according to modern 15 seismic provisions.Therefore, the rehabilitation/strengthening methodis very effectivefor post-earthquake 16 strengthening of typical substandard structures of developing countries. 17

The effectiveness of anovel Post-Tensioned Metal Strapping(PTMS)techniqueat enhancingthe seismic behaviourof asubstandard RC buildingwas investigated through full-scale shake-tabletests duringthe EU-fundedproject BANDIT.The building had inadequate reinforcement detailing in columns and joints toreplicateold construction practices.After thebarebuildingwas initially damagedsignificantly,itwas repairedand strengthened with PTMS to perform additionalseismic tests.The PTMS technique improvedconsiderablythe seismic performance of the tested building.Whilst the bare building experienced critical damageatan earthquake of PGA=0.15g, thePTMSstrengthened building sustained a PGA=0.35gearthquake without compromising stability.

No abstract

With increasing numbers of strength-deficient concrete infrastructure assets, strengthening and repair of concrete structures is becoming an issue of international importance. This study examines the bond behaviour of deep embedment (DE) glass fibre reinforced polymer (GFRP) and carbon FRP (CFRP) bars embedded into concrete prisms using an epoxy adhesive. The experimentally investigated parameters were the embedment length, FRP bar type and diameter, concrete compressive strength and hole diameter. The increase in embedded length enhanced the pull-out capacity for both GFRP and CFRP bar types. However, the bond strength and initial stiffness of the bond stress-slip curves decreased with the increase in embedded length. The specimens with DE CFRP bars had higher pull-out capacities and better bond performance than the corresponding specimens with DE GFRP bars. For the specimens with DE CFRP bars, the pull-out capacity increased with the increase in bar diameter and concrete strength but these two parameters did not affect the behaviour of the specimens with DE GFRP bars. The increase in hole diameter reduced the initial stiffness of the specimens with DE GFRP bars but affected neither the failure mode nor the failure loads. For the first time, this paper presents a mathematical 2 model for predicting the bond strength of DE FRP bars. The mathematical model was validated against experimental results and demonstrated to produce accurate predictions. It is envisaged that both the mathematical model and the experimental results will contribute to the development of future design guidelines for DE concrete shear strengthening.

The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription.