Reinforced Concrete Slabs Strengthened with Lap-Spliced Carbon TRC System

Materials (Basel). 2021 Jun 17;14(12):3340. doi: 10.3390/ma14123340.

Abstract

Construction with precast or prefabricated elements requires the connecting of structural joints. This study presents an accelerated construction method to strengthen reinforced concrete (RC) slab-type elements in flexure using precast lap-spliced textile-reinforced concrete (TRC) panels. The objectives of this study are to identify the tensile behavior of a TRC system with lap-spliced textile, and to experimentally validate the performance of the proposed connecting method by flexural failure test for the concrete slabs strengthened by TRC panels with lap-spliced textile. Twenty-one coupon specimens were tested in tension with two different matrix systems and three different lap splice lengths. The influence of the lap splice length and matrix properties on the tensile performance of the TRC system was significant. Five full-scale RC slabs were strengthened by the precast TRC panels with and without the lap splice, and was tested in flexure. The results of the failure test for the strengthened specimens showed that the ultimate load of the strengthened specimen with the TRC panel increased by a maximum of 24%, compared to that of the unstrengthened specimen. Moreover, the failure-tested specimens were re-strengthened by a new TRC panel system and tested again in flexure. The objective of the re-strengthening of the damaged RC slabs by the TRC panel is to investigate whether the yielded steel reinforcement can be replaced by the TRC panel. The initial cracking load and the stiffness of the re-strengthened specimens were significantly increased by re-strengthening.

Keywords: carbon textile; flexural strengthening; grout; lap splice; structural testing; tensile test; textile-reinforced concrete (TRC).