Studying Water to Cement Ratio and Steel Fiber Volume Fraction Effects on the Self-Compacting Steel Fiber-reinforced Concrete Fracture Parameters

In this research, efforts were made to study the effects of water to cement ratio (W/C) and steel fiber volume fraction (V_f (%)) on the fracture parameters of self-compacting steel fiber-reinforced concrete using both Work Fracture and Size Effect Methods. In an experimental program, a variety of water to cement ratio and volume of steel fibers were considered and five mix designs were prepared in two series. In the first, water to cement ratio were altered (Includes values :W/C=0.42, 0.52, and 0.62) with a constant volume of steel fiber (V_f=0.3%), and in the second, varied volume of steel fibers (Includes values: V_f=0.1, 0.3, and 0.5%) with a constant water to cement ratio (0.52) were considered. Results have shown that an increase in the water to cement ratio reduces the fracture energy, However, we see a different behavior in the lower water to cement ratio, while an increase in the volume of steel fiber not only increases the fracture energy causing the concrete to become more ductile, but it can also reduce the size effect greatly. G_F⁄G_f has been found for all mix designs about 11.81 and it has been concluded that the work fracture method yields more fracture energy than the Size effect method.