Flexural Behavior Analysis and Design Approach for R.C. Beams by Hybrid Reinforcement of Steel Rebars and HDPE Uniaxial Geogrids

Abstract

The objective of this study is to investigate a hybrid reinforcement method for concrete beams, which consists of steel rebars and HDPE (high-density polyethylene) uniaxial geogrids, by developing an experimental comparative investigation between utilizing different grades and layers of HDPE uniaxial geogrids as the primary reinforcement or as extra reinforcement to the steel rebars. The experiments for this investigation included 24 reinforced concrete beams in order to provide rich data for the flexural behavior analysis and design approach. For a detailed analysis, strain gauges were connected to steel rebars and HDPE uniaxial geogrids. Analysis of the results shows that the hybrid reinforcement method using steel rebars and HDPE uniaxial geogrids provided greater benefits (such as energy absorption capacity, ductility index, ultimate load, and steel-yield load) and more effective utilization (such as better flexural performance, lower deformation values corresponding to the steel-yield load, and greater benefits to cost ratios) than utilizing HDPE uniaxial geogrids as the primary reinforcement or utilizing the conventional reinforcement of steel rebars. Simple design equations were added to calculate the flexural bending capacity, the necessary HDPE uniaxial geogrids' grade, and the number of layers utilizing the HDPE uniaxial geogrids as the primary reinforcement or as extra reinforcement to the steel rebars.