Non-linear modeling of yield stress increase due to SCC structural build-up at rest

It is commonly considered that the yield stress of SCC increases linearly at rest. This increase is due to the SCC structural build-up. This behavior can be explained by the cement particle nucleation at the contact points. During the first dozens of minutes, the cement particle nucleation induces a linear increase of the yield stress in time. However, recent studies have shown that the trend of the yield stress increase becomes non-linear when considering a longer time (before the setting time). This study aims to provide a theoretical frame to describe this non-linear increase. The proposed model tends toward the linear model during the first dozens of minutes and follows the observed exponential law for a longer resting time. The discrepancy with the linear model is explained by two phenomena: an increase in the solid volume fraction and a decrease in the packing fraction due to cement particle nucleation. (C) 2016 Elsevier Ltd. All rights reserved.