Strengthening of high strength reinforced concrete thin slabs with CFRP laminates

Abstract

During the last few decades, engineers and researchers have used high-strength concrete to cast reinforced concrete (RC) slabs. Accordingly, the slab thickness and deadweight of buildings and structures were reduced significantly, which allowed engineers to construct higher and larger buildings. This research aims to study the behavior of 100 mm-thick RC slabs with concrete compressive strength of 70 MPa. A total of 18 RC slab specimens were cast and tested under two-point loading until failure. The specimens are divided into three groups having different flexural steel reinforcement ratios of 0.45, 1.00, and 1.79%, respectively. Each group of specimens was also strengthened with one and two layers of carbon fiber-reinforced polymer (CFRP) sheets externally attached to the soffit of the RC slabs to enhance their flexural capacity. The load-carrying capacity, failure mode, and ductility of the strengthened specimens were compared with control un-strengthened slabs. It was concluded that the strengthening of high-strength, thin concrete slabs increased the load-carrying capacities of the specimens in the range of 65% to 350%. This draws a conclusion on the best arrangement that can be used to utilize the CFRP properties and reach the best-value engineering fully.