Experimental Study on Concrete Slabs Reinforced with Polypropylene and Metallic Fibers.

This work focuses on the experimental study of the mechanical behavior through "three-point bending" tests on concrete slabs reinforced with two types of fibers: metal fibers (MF) and polypropylene fiber grids (PPF). The metal fibers come from machining waste of steel parts, randomly dispersed in the concrete, while the grids are made of polypropylene fibers. The bending tests are carried out on slabs with dimensions of [25x50x7] cm³. Compression tests are also performed on cylinders with a diameter of 160 mm and a height of 320 mm. The fibers are characterized in terms of mechanical strength and pull-out resistance. The composition of the concrete is determined using the experimental method known as the "Dreux-Gorisse" method. For this study, five metal fiber (MF) contents are selected (W=0.2%, W=0.4%, W=0.6%, W=0.8%, and W=1%). A reference concrete (BT) with a fiber content of (W=0%) is prepared to serve as a baseline. Two variants of polypropylene fibers, with small mesh (PPG/SM) and large mesh (PPG/LM), are also included. By comparing and contrasting the results obtained with those of Adeel Waris et al. [41], it is evident that the addition of metal fibers (MF) to concrete at a fiber percentage (W = 0.8%) improves both the strength and the bending rigidity better than the addition of polypropylene fiber grids, as well as better than the combination of steel fibers and rubber at volumes (Vf = 0.1(MF) + 2% (RC)) according to Adeel Waris et al. [41]. The comparison of the different results obtained also shows that metal fibers (MF) provide significant ductility to the material after the concrete cracks. Moreover, the metal fibers used limit the crack openings.