Prediction of lateral form pressure exerted by concrete at low casting rates

International audienceIn this work, we propose to extend theOvarlez and Roussel model, for estimating lateralform pressure exerted by fresh concrete, to low castingrates and long duration formwork filling. In this case,the assumption of a linear increase of the concreteyield stress with time at rest is imprecise. Thisassumption is valid for approximately 1 h at rest afterplacing and may lead to an overestimation of thelateral pressure for a longer period. Based on chemicalarguments and experimental observations, it has beenshown that the yield stress increases exponentiallyover time. The same fundamental physical assumptionsmade by Ovarlez and Roussel are used to predictthe lateral pressure exerted on formwork. Comparisonof the proposed model with experimental measurementsshows that, pressure can be predicted with anaccuracy comparable to the Ovarlez and Rousselmodel for casting times less than 1 h