Influence of the sulphate content of recycled aggregates on the properties of cement-treated granular materials using Sulphate-Resistant Portland Cement

The present work discusses the results of an experimental study investigating the performance of cement-treated granular materials, which were prepared from natural aggregates, recycled concrete aggregates, crushed clay bricks and gypsum. Recycled aggregates can potentially contain large amounts of acid-soluble sulphates. High sulphate contents can lead to the formation of ettringite, which causes dimensional instability in cement-treated materials. The tested samples were manufactured with different types of cement (CEM II and Sulphate-Resistant Portland Cement) and different compositions of the recycled materials to observe the effects of the sulphate content on the mechanical behaviour and the dimensional stability. As a result, the influence of the amount of sulphates on the deformation was determined, which is an aspect that must be considered in applications of this recycled product in road layers. (c) 2014 Elsevier Ltd. All rights reserved.