Shear Strength of Reinforced Concrete Circular Cross-Section Using Geo-Grids and Steel Fibres

Abstract

Reinforced concrete members with circular cross-sections are used frequently in construction practice. They are used as columns, piers, and piles because of their identical properties in all direction. The present research deals with the study of shear strength of the RC circular sections using geogrids and steel fibres, where the steel stirrups are partially replaced by the geogrids. Geogrids being good at tension and flexible in nature, the idea to use it as a stirrup was generalized for the research. Addition of steel fibres known to resist the cracking in concrete, both geogrids, and steel fibres was used to study the performance of the concrete. Sixteen specimens were casted with parameters such as steel stirrups spacing (75 mm, 100 mm, 150 mm, 450 mm and 700 mm), use of type of concrete (Reinforced Concrete and Steel Fibre Reinforced Concrete) and use of different tensile strengths of geogrids (100 KN/m and 200 KN/m). The testing of circular specimens was carried out on a loading frame having a hydraulic jack of capacity 600 KN. Each specimen was simply supported and subjected to a point load at midspan. The load-deformation curves were plotted for each specimen and compared for the ultimate load, secant stiffness, energy dissipation, and displacement ductility. The test results revealed that application of geogrids along with the steel fibres significantly improved the ductility and strength of the specimen.