Experimental investigations on the bond performance of reinforced concrete beam with lap splices after fire exposure

The manufacturing and transportation limitations necessitate splicing of the reinforcing bars for the construction of most reinforced concrete (RC) structures. Lap splices present a particular challenge in case of a fire incident, as the local damage in the concrete cover region can significantly affect the structural performance. There are multiple studies on post-fire bond behaviour, however, only a few studies focused on its implications at the structural level. In order to bridge this gap, the research reported herein focused on the post-fire performance of lap splices. RC beams without and with tension lap splices were tested in four-point bending, whereby different lap lengths were considered (20–50 times the bar diameter). The beams were exposed to a standard ISO 834 fire for 60 minutes and bending tests were performed in residual state thereafter. To avoid possible explosive spalling, 1kg/m 3 of polypropylene fbers were added to the concrete mix. It is observed that fire has a strong impact on the beams with lap splices whereas beams with continuous reinforcement almost maintain their original flexural capacity in post-fire state. The results are compared with the results obtained in the previous studies by the authors using beam-end specimens. The design concept proposed forms the basis of the new provisions in fib Model Code 2020 for the design of lap splices under fire. • Experimental investigation of post-fire bond behaviour of reinforcement concrete beam with lap splice. • The bond performance of lap-splice exposed to fire have been investigated and subsequently compared to results of reference beams(no-fire). • Different splice lengths have been considered for the investigations. • Bond performance is investigated employing full-scale beam subjected to ISO 834 fire for a fire exposure duration of 60 minutes. • The results are compared with the model code 2020 design/assessment model for splice/anchorage after fire.