Flexural and Bond Behavior of Concrete Beams Strengthened with CFRP and Galvanized Steel Mesh Laminates

Abstract

Carbon fiber–reinforced polymer (CFRP) composites are effectively and predominantly used for flexure strengthening of RC beams. Recently, new emerging composite materials known as galvanized steel mesh (GSM) sheets, which are comprised of unidirectional ultrahigh-strength steel wire meshes, are gaining considerable attention in strengthening applications. The main aim of this paper is to compare the test results of RC beams strengthened with medium-density GSM (MSM) and high-density (HSM) laminates with that of CFRP laminates. Accordingly, a total of six RC beams were strengthened in flexure with equivalent CFRP, MSM, and HSM laminates, in addition to two control unstrengthened beam specimens. All beam specimens were subjected to symmetrical monotonic loading testing, and strain data were recorded along with deflection at the beams midspan. Experimental results showed that HSM laminates enhanced the flexural strength, stiffness, cracking performance, energy absorption, and ductility of RC beams compared with CFRP and MSM laminates. In addition, flexural bond tests were conducted on prism samples to compare the bond behavior between each of the three laminates and concrete interface. The test results also showed that HSM laminates failed at higher attained load levels than CFRP and MSM laminates. Current design guidelines were also used to predict the nominal flexural capacity of the control and strengthened RC beams. The results showed that the predicted ultimate load is in good agreement with the experimental results and the difference was in the range of 0.4%-4%, respectively. Therefore, it has been concluded that GSM laminates can be used as an effective composite material for flexural strengthening of RC beams.