Compressive strength and hydration processes of concrete with recycled aggregates: Fid-Bau Portal

Compressive strength and hydration processes of concrete with recycled aggregates

Koenders, Eduardus A.B. / Pepe, Marco / Martinelli, Enzo

Abstract This paper deals with the correlation between the time evolution of the degree of hydration and the compressive strength of Recycled Aggregate Concrete (RAC) for different water to cement ratios and initial moisture conditions of the Recycled Concrete Aggregates (RCAs). Particularly, the influence of such moisture conditions is investigated by monitoring the hydration process and determining the compressive strength development of fully dry or fully saturated recycled aggregates in four RAC mixtures. Hydration processes are monitored via temperature measurements in hardening concrete samples and the time evolution of the degree of hydration is determined through a 1D hydration and heat flow model. The effect of the initial moisture condition of RCAs employed in the considered concrete mixtures clearly emerges from this study. In fact, a novel conceptual method is proposed to predict the compressive strength of RAC-systems, from the initial mixture parameters and the hardening conditions.

Highlights • The concrete industry is more and more concerned with sustainability issues. • The use of recycled aggregates is a promising solution to enhance sustainability. • Recycled aggregates affect both hydration processes and compressive strength. • A fundamental approach is proposed to unveil the influence of recycled aggregates. • Some experimental comparisons are presented to validate the proposed approach.