Effect Of Coarse Aggregates And Steel Bars Reinforcement On Fracture Behaviour Of Steel Fibrous Concrete

One of the underlying inciples of fracture mechanics is that unstable fracture occurs when the stress intensity. factor at the crack tip reaches a critical value . This value for mode I deformation and small crack tip plastic deformation is designatedKrc. Krc represents the inherent ability of a material towithstand a given stress - field intensity at the crack tip .. and resist progressive tensile crack extension under plane strain conditions .In the present work, the fracture behavior of concrete beamsreinforced by steel bars and steel fibers was investigated. Theeffect of fiber volume fraction, notch - depth and different typesof coarse aggregate on the fracture toughness of concretebeam specimens of dimensions 6 x 15 x 65 cm and reinforcedwith different areas of steel bars were studied The used fibervolume fraction were 0.0 and 1.0 % , the notch / depth ratioswere 0.1 , 0.3 , 0.5 and steel bars reinforcement areas were 206 mm and 2 0 8 mm. Two different types of coarse aggregateused in the mIX (dolomite and gravel). The flexural strengthof unnotched beams of the same dimensions , splitting tensilestrength of standard cylinders and compressive strength of standardcubes were measured for the considered fiber volume fraction andfor the two types of coarse aggregate mentioned above.