The enhanced performance of CFST beams using different strengthening schemes involving unidirectional CFRP sheets: An experimental study

摘要: Abstract Concrete-filled steel tube (CFST) beam, like any conventional structural member, for several reasons need strengthening, such as by making upgrades to carry extra loads or make repairs owing degradation attributed aging, fire, and fatigue. This study experimentally investigates the strengthening behaviour of circular rectangular simply supported CFST beams using unidirectional carbon fibre reinforced polymer (CFRP) sheets, in which partial-unilateral (partial), full-unilateral (full), full-bilateral (combined) schemes with varied layers lengths are used. The results show that moment capacity, energy absorption flexural stiffness strengthened beam significantly improved increase CFRP layers. For example, capacity increased about 26% 38% when they were partially two three layers, respectively. Also, laid along 75% 100% their lengths, fully its length, all achieved almost same load improvements (+26% +28%) comparison control means 50% amount sheets even more can be saved improvement achieved. 21.8% example. Moreover, values fairly agreed those predicted from existing standards (AISC, EC4, BS5400, AIJ) after including effects CFRP.