A method for mix-design of fiber-reinforced self-compacting concrete

The addition of fibers to self-compacting concrete (SCC) may take advantage of its superior performance in the fresh state to achieve a more uniform dispersion of fibers, which is critical for a wider structural use of fiber-reinforced concrete. Some useful, mainly empirical, guidelines are available for mix design of fiber-reinforced SCC. In this work a “rheology of paste model” is applied to the mix design of Steel Fiber Reinforced SCC (SFRSCC). Fibers are included in the particle size distribution of the solid skeleton through the concept of an equivalent diameter, defined on the basis of the specific surface. The influence of fibers (type and quantity) on the grading of solid skeleton, minimum content and rheological properties of the paste required to achieve the required self-compactability and rheological stability were studied. Tests were conducted on both plain and fiber-reinforced concrete made with a variety of mix compositions. In addition, rheological tests were made with corresponding cement pastes.