Creep and shrinkage of recycled aggregate concrete

This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from construction waste and concrete work demolitions. The main aim of this work was to determine creep and shrinkage variations experienced in recycled concrete, made by replacing the main fraction of the natural aggregate with a recycled aggregate coming from waste concrete and comparing it to a control concrete. The substitution percentages were 20%, 50% and 100%. Fine natural aggregate was used in all cases and the amount of cement and water–cement ratio remained constant in the mixture. It was possible to state that the evolution of deformation by shrinkage and creep was similar to a conventional concrete, although the results after a period of 180 days showed the influence of the substitution percentage in the recycled aggregates present in the mixture. In the case when 100% coarse natural aggregate was replaced by recycled aggregate there was an increase in the deformations by creep of 51% and by shrinkage of 70% as compared to those experienced by the control concrete.