Study of brick masonry columns confined with CFRP composite

Fiber-reinforced polymer (FRP) composites are more and more used in the building trade for the set up of reinforcing and repair devices. As known, FRP composites offer higher strength and Young modulus than traditional steel devices, but nowadays technologies are not able to produce pretension of the wrap in civil engineering strengthening applications. Moreover, when confining compressed masonry columns with FRP composites, the effective contribution of the composite cannot be accurately evaluated. In the present paper, some theoretical relationships available in literature are analyzed, regarding the evaluation of confinement effect on wrapped masonry columns. The reliability of these formulations is investigated, comparing the theoretical values with unixial and triaxial experimental test results; unixial tests were carried out both on plain and wrapped brick masonry samples. Experimental results are shown not to fit to the formulas of the literature and the reasons of the discrepancy were searched for in the mechanical process that produces failure.