Demoulding vertical elements: Recommendations for apply maturity functions

Abstract Many standards recommend different minimum demoulding times depending on site conditions. Different parameters are taken into account in determining the minimum demoulding time, but the only one that is always taken into account is concrete temperature. Therefore, a methodology for determining the minimum demoulding times for vertical elements of self-compacting concrete (SCC) based on maturity functions is studied. Maturity functions establish a relationship between maturity and in-situ resistance. While maturity may be measured by measuring the temperature over time, there are different option for determining resistance in-situ, and thus the objective of this work is focused on methods for measuring resistance at early ages. An experimental study was carried out to establish which method for determining resistance in-situ is best suited to the determination of the resistance-maturation curve. To that end, the suitability and consistency of each method were studied. In addition, an experimental validation of the methodology was carried out, in which the demoulding methodology was applied to 11 columns tested at a construction site. The validation was carried out with two different types of SCC and different types of formwork.