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

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.

Flexural Behavior Analysis and Design Approach for R.C. Beams by Hybrid Reinforcement of Steel Rebars and HDPE Uniaxial Geogrids

“…As per previous studies, the efficiency of geogrids as concrete-beam reinforcement in ascending order according to their type was triaxial, biaxial, and uniaxial geogrids. Furthermore, the uniaxial geogrids provide the most effective utilization when used as extra reinforcement to the steel rebars for concrete slabs (Mohamed et al, 2020). Therefore, the type of geogrid used in this research was HDPE uniaxial geogrids (UG).…”

“…Group B contained 13 concrete beams, 12 of which were reinforced by two 8-mm diameter plain steel rebars as primary lower-side reinforcement in addition to different grades and number of layers of HDPE uniaxial geogrids as extra lower-side reinforcement, while the rest of group B's concrete beams were reinforced with two 8-mm diameters plain steel rebars as lower-side reinforcement, which was considered as a concrete control-beam. It is worth noting that HDPE uniaxial geogrids as concrete reinforcement provide better performance when they are combined with a reasonable steel rebar ratio (not a minimum steel rebar ratio) (Mohamed et al, 2020); therefore, this condition was taken into consideration throughout the arrangement of the steel rebars.…”

“…HDPE uniaxial geogrids as a concrete reinforcement perform better when they are tightened prior to the pouring of concrete (Mohamed et al, 2020); therefore, during the connecting of the HDPE uniaxial geogrids' lower-side reinforcement, they were tightened to ensure that they remained straight during the pouring of concrete. However, for group A, the HDPE uniaxial geogrids reinforcement was did not stay perfectly straight because the steel cages were not steady due to the absence of lower-side steel rebars, while for group B, the HDPE uniaxial geogrid reinforcement was kept straight because the steel cages were steady due to the presence of lower-side steel rebars.…”

“…Several studies have been conducted on the utilization of geogrids as a material for reinforcement in Portland cement concrete overlays and thin members (Tang et al, 2018a). Some studies have also been conducted on the utilization of geogrid materials either for the strengthening of concrete slabs and beams (Saranyadevi et al, 2016;Ahmed Shaban, 2019), for reinforcement of concrete slabs (Al Qadi et al, 2015;Tang et al, 2019;Mohamed et al, 2020), or for reinforcement of concrete beams (El Meski and Chehab, 2014;Shobana and Yalamesh, 2015). The highlights of this research are:…”

Flexural Performance and Toughness Characteristics of Geogrid-Reinforced Pervious Concrete with Different Aggregate Sizes

“…Al-Hedad and Hadi [ 20 ] showed that geogrid-reinforced concrete slab had improved flexural performance and cracking resistance. Mohamed et al [ 21 ] conducted a four-point bending test on geogrid-reinforced concrete slabs and indicated that triaxial geogrids could provide lower deflection values and higher first-crack load values for geogrid-reinforced concrete slabs. Meng et al [ 22 ] studied the flexural behavior of geogrid-reinforced pervious concrete beam with a different geogrid layer number at various positions.…”