Behavior of Geogrid-Reinforced Portland Cement Concrete under Static Flexural Loading

Geogrids have been investigated by a limited number of studies as a potential alternative to steel reinforcement for Portland cement concrete (PCC), especially in situations where using steel reinforcement may not be suitable due to constructability and durability limitations. This study aims to investigate the flexural behavior of simply-supported concrete beams reinforced by geogrids, which would aid in assessing the potential use of geogrids for concrete structures such as overlays and other thin sections. Another objective of this study is to examine the potential benefits of embedding geogrids in PCC, and to investigate the mechanism and effectiveness of geogrid reinforcement in PCC. Plain and geogrid-reinforced concrete beams were fabricated and tested under a static four-point flexural bending load. The midspan deflection and crack mouth opening displacement (CMOD) of the beams were recorded during loading. Additionally, for geogrid-reinforced beams, strain gages were attached on the geogrids to monitor the strains that developed in geogrids. Results reveal that the geogrid primarily contributes to improving the ductility of the post-peak behavior of plain concrete and to delaying the collapse failure of concrete beams. Strain measurements of the geogrids indicate that the geogrids were activated and mobilized instantly upon the application of the flexural load. Both the strain measurements and observations of the geogrids post failure suggest that there was no slippage between the geogrids and the concrete.