Flexural Behavior of Reinforced Concrete Slabs Reinforced with Innovative Hybrid Reinforcement of Geogrids and Steel Bars

Ramy Mohamed,A.M El Sebai,Ahmed Gabr

doi:10.3390/buildings10090161

Abstract

This paper aims to innovate a hybrid reinforcement system for concrete slabs, consisting of geogrids and steel bars, by conducting an experimental comparative study between using different types, tensile strengths, and layers of geogrids as additional reinforcement to steel bars in comparison to conventional steel-reinforced concrete control slab. These concrete slabs were tested under a four-point loading system until they failed due to bending. As an addition, strain gauges were attached to the concrete slabs bottom reinforcement (geogrids and steel bars) to provide a close examination of geogrids and steel bars as a hybrid reinforcement system. Results show that the innovated hybrid reinforcement system of uniaxial geogrids and steel bars more preferred as concrete slabs reinforcement as it provided more benefits values (including, but not limited to, initial-peak load, steel-yield load, post-peak load, displacement ductility index, and energy absorption capacity) and more efficient utilization (including, but not limited to, higher benefits to cost values and better flexural performance) than the case of using conventional reinforcement of steel bars and the cases of using triaxial geogrids as additional reinforcement to the steel bars; however, triaxial geogrids provide lower deflection values and higher first-crack load values.

Highlights

Geogrids are one of the polymeric materials classified under geosynthetics materials and are mainly made from polymers, such as polyester, polyethylene, and polypropylene [1]
The sudden drop in the load was with a percentage of 19% for the concrete control slab, a percentage varying from 8% to 30% for group number one’ concrete slabs, and a percentage varying from 26% to 32% for group number two’
The sudden deflection increase was with a percentage of 19% for the concrete control slab, a percentage varying from 7% to 38% for group number one’ concrete slabs, and a percentage varying from 11% to 17% for group number two’ concrete slabs, with no correlation to the tensile strength of geogrids and the number of geogrids’ layers

Summary

Introduction

Geogrids are one of the polymeric materials classified under geosynthetics materials and are mainly made from polymers, such as polyester, polyethylene, and polypropylene [1]. This characteristic enables them to transfer the tension force to a larger area of soil. The use of geogrids as reinforcing material is expanding towards the pavement system, especially in the following fields: Reinforcing elements for asphalt layers, stabilizing the unbound layers [3], as an interlayer system in overlay applications [4], as shrinkage reinforcement in Portland cement concrete pavements [5], and as an interlayer system to reduce reflective cracking in concrete overlays [6,7] or asphalt overlays of jointed concrete pavements [8,9]. Little researches have been performed on geogrids used as reinforcement material in Portland cement concrete thin members and overlays [10]

Objectives

Results

Conclusion