Bond Behavior Investigation Between Steel Reinforced Grout Composites and Masonry Substrate

Abstract

Most ancient and historical buildings are masonry structures. One of the innovative methods to enhance masonry structures is the steel-reinforced grout (SRG) with ultra-high tensile strength steel cords enclosed in a mortar matrix. Many applications have been addressed for this method, of which the most important ones are improving the load-carrying capacity and seismic performance of masonry structures. However, SRG bond strength, as a crucial key to design reinforcement of masonry elements, has not been investigated appropriately yet. This study is aimed to present an experimental investigation concerning SRG bond behavior applied to masonry substrates. To explore the effect of bond length and width, test set-up configurations, and loading rate on failure mode and bond strength, single-lap shear tests with two various test set-ups were carried out on masonry prism in the laboratory. Different failure modes, the peak stresses, slip correlative to the peak load and the magnitude of masonry prism rotation during the experiments are considered as evaluation metrics utilized in this study. The results showed that the Mode-II failure is dominant for all the experimental specimens. Moreover, the effective bond length was obtained greater than 150 mm; the failure mode of SRG-masonry composite strips with bonded lengths shorter than 150 mm was recognized by the detachment of the top matrix layer of composite from the bottom layer.