Evaluation of the Durability Properties of Engineered Cementitious Composites Incorporating Recycled Concrete as Aggregate

Abstract

Engineered cementitious composites (ECC) possess outstanding mechanical properties which make them suitable for construction and repair applications. However, the high cost and limited supply of the special silica sand used as the only aggregate in ECC have limited its widespread use. A recent study has shown that recycled concrete fines can be used as a replacement for conventional sand in ECC without much detrimental effect on its mechanical properties. However, the corresponding effect of the recycled concrete as an aggregate on the durability of ECC is unknown. Therefore, this study was carried out to investigate the durability properties of ECC mixtures incorporating recycled concrete fines as aggregates. The durability of the mixtures was assessed in terms of shrinkage and permeability properties as these are very critical to its applications. This study showed that the use of recycled concrete as aggregate up to 100% replacement of the silica sand resulted in about a 40% reduction in drying shrinkage. However, chloride ion penetration, permeable voids, and water absorption of ECC mixtures incorporating 100% recycled concrete as aggregate increased by 19%, 28%, and 34%, respectively. Sustainability and cost assessments of the ECC mixtures indicate that the use of RC as aggregate in ECC mixtures is sustainable and economical.