Seismic shear strengthening of R/C beams and columns with expanded steel meshes

摘要

This paper presents results of an experimental study to evaluate a new retrofit technique for strengthening shear deficient short concrete beams and columns. In this technique a mortar jacket reinforced with expanded steel meshes is used for retrofitting. Twelve short reinforced concrete specimens, including eight retrofitted ones, were tested. Six specimens were tested under a constant compressive axial force of 15% of column axial load capacity based on original concrete gross section, A_g, and the concrete compressive strength, f′_c. Main variables were the spacing of ties in original specimens and the volume fraction of expanded metal in jackets. Original specimens failed before reaching their nominal calculated flexural strength, M_n, and had very poor ductility. Strengthened specimens reached their nominal flexural strength and had a ductility capacity factor of up to 8 for the beams and up to 5.5 for the columns. Based on the test results, it can be concluded that expanded steel meshes can be used effectively to strengthen shear deficient concrete members.