Compressive Strength of Bottle-Shaped Compression Fields of Fiber Reinforced Concrete Members

Applying load to a structural member may result in a bottle-shaped compression field especially when the width of the loading is less than the width of bearing concrete members. At the Building and Construction Department – the University of Technology-Iraq, series tests on fibre reinforced concrete specimens were carried out, subjected to compression forces at the top and bottom of the specimens to produce compression field. The effects of steel fibre content, concrete compressive strength, transverse tension reinforcement, the height of test specimen, and the ratio of the width of loading plate to specimen width were studied by testing a total of tenth normal strength concrete blocks with steel fibre and one normal strength concrete block without steel fibres. Based on experimental results; all the test specimens failed with the splitting of concrete directly under the loading plate. Increased the uniaxial compressive strength of concrete increases the maximum bearing capacity of compressive stresses. The load-transverse deformation initially behaves linearly and shows some nonlinearity before failure. Addition of steel fibre to normal strength concrete or presence of transverse reinforcement, delay the reaching of maximum compressive stress after the presence of the first crack