Mechanical and rheological properties of steel fibre reinforced self - compacting concrete

Abstract

Main objective of the research was to further understand the different parameters affecting performance of SFR-SCC with different steel fiber volumes and types. Fresh and hardened state properties of these materials were investigated by using several experimental methods. For this purpose 5 mixes; plain and reinforced with 2 different fiber volumes (0.5 and 1.0%) and two different fiber lengths; were produced. Flowa bility and rheology as well as static and dynamic segregation resistance of the above mentioned mixes were studied in the fresh state. Specimens with varying sizes were produced with these 5 mixes. Six different width and depth (30 mm to 100 mm), four different length (200 mm to 425 mm) were used to investigate the effect of shear span to depth ratio (a/d) and specimen thickness to fiber length (t/fL) on the mechanical per formance of small size beams. As a result 35 different specimen groups were obtained. Compressive strength, splitting tensile strength and 4-point bending tests were carried out on these specimens for thoroughly evaluating mechanical performance and cracking mechanisms. Detailed fiber orientation tests were carried out on the selected specimens in the hardened state, to understand the fiber orientation states of the specimens and their effects on the resulting performance. The results showed that fiber orientation in the casting direction can be made possible by using a casting flow methodology. Both of the investigated parameters (a/d and t/fL ratios) and varying fiber parameters were found to highly affect resulting mechanical performance and cracking patterns under bending. 3 point bending tests on notched specimens were done for modeling bending behavior by using an existing model and the model was further developed by introducing new parameters for short FRC.