Flexural Behavior of Reinforced Concrete Beams with Geogrid - Experimental Study

Abstract

Geogrids are categorized as one of the geosynthetics materials that are used for soil stabilization and reinforcing of earth structures such as earth walls and dams. This research investigated the effect of using uniaxial geogrids as additional reinforcement, in addition to, steel fibers in the concrete mix, on the flexural behavior of beams. The experimental research work comprised of testing thirteen simply supported reinforced concrete (R.C) beams which were tested up to failure under four-point loading. The variables of this study are: the volume of steel fibers (0.0, 0.5, 1.0 %), number of geogrid layers (one, two, and three layers), the shape of the geogrid layers, and the longitudinal reinforcement percentage. The mid-span deflection, failure loads, ductility, crack patterns, steel, concrete and Geogrid strains of the beams were reported and compared. The test results concluded that the addition of Geogrid layers as a reinforcing technique proved to be an effective tool to improve the flexural behavior of R.C beams and improve the cracking patterns. The number of geogrid layers used in the beams plays a significant effect in increasing the failure loads and decreasing the deflections of the beams. The addition of steel fibers in R.C beams, in addition to, Geogrid layers increases the cracking loads, failure loads and reduces the deflection of beams at failure loads. Increasing the fiber content from (0.5%) to (1%) had a slight effect on increasing the maximum carrying capacities of the beams. Addition of U-shaped Geogrid layers had a considerable effect on increasing the failure loads rather than the addition of Geogrid layers in the tension zone only.

Numerical Investigation of RC Beams Reinforced With Geo-grid And Steel Fiber in The Flexural

“…By increasing the bottom reinforcement ratio to 1.5% in beam (s31), the failure load increased to 223.2 KN and, the deflection decreased to 8.2mm.  For group (7) with geogrid volumetric ratio 4.5%: the maximum deflection recorded is 10.87 mm at a failure load of 97.2 KN for beam (s32). By increasing the bottom reinforcement ratio to 1.5% in beam (s37), the failure load increased to 203.4 KN, the deflection decreased to 5.79mm.…”

“… Fig. 24b shows that the deflection of group (7) with geogrid volumetric ratio = 4.5% were decreased by 21.8%, 23.4%, 42.1 %, 45.2and 46.7% for beams s33, s34, s35, s36 and s37 respectively; compared to specimen s32.  Fig.…”

“…Load-deflection curve of a group (6) Load-deflection curve of a group (7) Load-deflection curve of a group (8) Load-deflection curve of a group ( 9)…”