Experimental characterization of tensile strength of steel and fibre rovings also under environmental conditioning

The efficiency of the strengthening techniques by externally applied materials can be improved enhancing the debonding strength of the reinforcement from the support by the use of connectors (anchor spikes) consisting of unidirectional bundles of fibres embedded in concrete or masonry by means of organic or inorganic matrices. The use of connectors is suggested in various codes and guidelines of strengthening techniques by composite materials and provisions for their application are given, but currently there are no details for the qualification of the material. In order to investigate anchor spikes made of glass, basalt, aramid, carbon, PBO and steel, a large experimental campaign was carried out at the Materials and Structures Laboratory of the University of Sannio. The tests allowed to evaluate the mechanical characteristics (tensile strength, modulus of elasticity, deformation at the maximum load) of the anchor spikes constituted by only dry fibres, not impregnated, also as a result of environmental conditioning such as freezing and thawing, controlled humidity, alkaline and saline environment.