Shear strength testing of basalt-, hybrid-, and nano-hybrid fibre-reinforced polymer bars

Over the past decades, using of sustainable materials in construction is a challenging issue, thus Fibre Reinforced Polymers (FRP) took the attention of civil and structural engineers for its lightweight and high-strength properties. The paper describes the results of the shear strength testing of three different types of bars: (i) basalt-FRP (BFRP), (ii) hybrid FRP with carbon and basalt fibres (HFRP) and (iii) nano-hybrid FRP (nHFRP), with modification of the epoxy matrix of the bar. The hybridization of carbon and basalt fibres lead to more cost-efficient alternative than Carbon FRP (CFRP) bars and more sustainable alternative than Basalt FRP (BFRP) bars. The BFRP, HFRP and nHFRP bars with different diameters ranging from O4 to O18 mm were subjected to shear strength testing in order to investigate mechanical properties and the destruction mechanism of the bars. Obtained results display a slight downward trend as the bar diameter increase, which is the most noticeable for HFRP bars. In most of the cases, BFRP bars were characterized by greater shear deformation and less shear strength compared to HFRP and nHFRP bars. Performed testing may contribute to comprehensive understanding of the mechanical behavior of those types of FRP bars.