Effect of geogrid on the structural behavior of reinforced concrete beams

Now, using of geogrids as strengthening material are extend used, especially to enhancement of concrete elements as inter layers concrete applications, eight beams were tested to explain the effect of geogrid on the behavior of reinforced concrete beams. Beams tested had equal cross-sectional dimension (100 mm x 200 mm), compressive strength (f’c = 30 MPa), with a simply span length equals 1150 mm, with shear reinforcement (Ф4 @100mm C/C) and subjected to two point load. The tested beams were divided into two groups according to the presence of geogrid layer, with and without geogrid. Each group consists of four specimens, which were sub-divided according to the flexural reinforcement ratio that ranges from (0 to 0.0263). During the tests, it was noted that, the load deflection curve for beams with geogrid layer were stiffer and the percentage of stiffening was increased with increase of the flexural reinforcement ratio. The maximum applied load for beams with geogrid layer were higher than conventional beams without geogrid layer under the same conditions, while, the deflection values for beams with geogrid layer was lower than conventional beams without geogrid layer. The first crack load of beams with geogrid was greater than conventional beams without geogrid layer. So, the geogrids layer offer great enhancements to concrete properties and performance from the first cracking load, load-deflection response, reduce the cracks width and number and ultimate strength of tested in comparison to the conventional beams. (paper)