Proportioning of self-compacting steel-fiber reinforced concrete mixes based on target plastic viscosity and compressive strength: Mix-design procedure & experimental validation

This paper presents a novel proportioning methodology for self-compacting steel-fiber reinforced concrete (SCSFRC), based on a previous methodology for plain self-compacting concrete [Journal of Sustainable Cement-Based Materials 5:4 (2016) 199-216 & 217-232]. The procedure is based on the target plastic viscosity and the compressive strength required for the mix and it accounts for fiber parameters such as volume fraction and aspect ratio. The procedure is valid for fiber contents up to 1% and for compressive cube strengths within the range of 30-80 MPa. The effective plastic viscosity of the SCSFRC is estimated from the plastic viscosity of the cement paste by means of micro-mechanical models that consider fibers as a phase of the mix. The procedure can be programmed numerically to generate practical mix-design charts to determine the dosage of the components. The paper provides an example of an application that uses these design charts. Likewise, the methodology is validated through the design of six mixes, which are actually prepared in the laboratory and whose properties are measured in fresh and hardened states.