Experimental investigation on the flexural and post-cracking behaviour of geogrid-reinforced concrete overlays

Abstract

Innovative materials are on the rise as alternatives to steel reinforcement in concrete structures. Recently, the use of polymeric geogrids as reinforcement elements has expanded into Portland cement concrete (PCC) overlays rehabilitation. Research conducted to date has indicated that the use of geogrids as reinforcement in concrete pavements shows both post cracking ductility and superior load capacity. Although this topic is not so explored in the literature, the use of geogrids in thin concrete overlays, pathway, pedestrian sidewalks and floating slabs is promising and gives a new employment area for the use of geogrid reinforcements. This paper presents an experimental investigation on the flexural behaviour, post-cracking and fracture energy performance of geogrid-reinforced concrete beams under four-point bending test. Different geogrids were embedded at one-third depth (from bottom) of concrete beam specimens (500 × 150 × 150 mm). The PCC mix was prepared using Ordinary Portland Cement (OPC grade 53) with compressive strength of 40 MPa. Results confirmed that the flexural performance and post-cracking resistance of the concrete beam specimens could be enhanced by the presence of geogrids, as evidenced by load-deflection response, crack mouth opening displacements and change in failure mode. Triaxial geogrids showed 11% increase in flexural strength of concrete beam, highlighting the potential benefits of geogrids reinforcements in PCC overlays.