Experimental investigation of concrete cylinders confined by carbon FRP sheets under monotonic and cyclic axial compressive loads

A consequent investigation is conducted on the mechanical behavior of concrete confined by carbon FRP material. The behavior of concrete cylinders with compressive strength 25.2 MPa and 51.8 MPa, confined by high E-modulus carbon sheet (377 GPa) is presented. The concrete cylinders were wrapped with 1, 2, 3 and 5 layers of carbon FRP sheet and subjected to monotonic and cyclic axial compressive loading. Teflon sheets were used between concrete and steel bearing platens to reduce friction. Pretests were made to estimate the proper overlap length of the external layer. The confining effect is addressed in terms of concrete strength, ductility and expansion. Considerable levels of strength and strain at failure were achieved even for high strength concrete for monotonic and cyclic mode of loading.