Flexural behavior of stone slabs strengthened with reinforced mortar

Abstract

This paper describes an experimental and analytical program focused on developing a strengthening technique to enhance the flexural performance of stone slabs. The technique involves the use of reinforced mortar bonded to the soffit of the stone slabs, which can be used for strengthening of stone slabs in existing structures, or manufacturing of composite stone members for new constructions. The experimental program consisted of flexural testing of strengthened stone slabs and an unstrengthened specimen serving as the benchmark. The amount of reinforcement ratio and mortar strength were varied as the test variables. An analytical model was also developed to predict the cracking and ultimate moment of strengthened stone slabs. The unstrengthened specimen failed suddenly in a brittle fashion; however, the strengthened stone slabs experienced a ductile failure mode and developed a higher flexural strength. As expected, the enhanced performance was proportional to the reinforcement ratio, but the strength of mortar affected only the cracking moment. The stone slab and the reinforced mortar layer exhibited good composite action, and no obvious interfacial failure was observed. The analytical model developed could reasonably predict the cracking and ultimate moment of stone slabs strengthened with reinforced mortar.