New model to estimate plastic viscosity of eco-friendly and conventional concrete

This paper presents a new rheological model for estimating plastic viscosity of eco-friendly concrete (concrete with a high rate of mineral addition) and ordinary concrete. The proposed model is based on the assumption that the concrete is divided into two scales: paste (water, cement, addition and superplasticizer) and aggregate (sand and gravel). Model predictions are evaluated using large experimental results of 44 mixtures. The used results have been obtained with recent developed rheometer witch new blade geometry (in form of a perpendicular double U) was used. This new geometry minimizes segregation of concrete during the rheological test. The evaluation of the proposal model with experimental results showed that, the model fits well with viscosity of eco-friendly concretes (with mineral addition) as well as ordinary concrete (without addition). The developed model describes well the concrete viscosity depending on the nature and the rate of replacement with mineral addition and the effect of the superplasticizer. The validation showed that this model predicts concrete viscosity with an error of about ±11%.