Design of Sustainable High-Ductile Engineered Cementitious Composites with Limestone Calcined Clay Cement

Abstract

Limestone calcined clay cement (LC3) is a new blend of cement prepared from high amounts of limestone and calcined clay. Unlike Ordinary Portland Cement (OPC) that is made of 95% clinker, LC3 development requires only 50% clinker, which make it a highly sustainable material com-pared to OPC. Although, engineered cementitious composites (ECCs) have special characteristics in terms of enhanced tensile strength and tensile strain capacity and low permeability, their high binder and OPC amounts than other fiber reinforced concretes influenced negatively the economic and environmental benefits of these composites. In this study, the effect of using LC3 instead of OPC in different ECC compositions was investigated. For this purpose, OPC was replaced completely with LC3, and various amounts of fly ash type-F (FA) were incorporated with LC3 at various FA/LC3 ratios of 0, 0.8, 1.2 and 1.5. The fresh, mechanical and durability properties were considered by testing the flowability, compressive and flexural strengths, ductility and cracking behavior, as well as the chloride permeability of LC3-based ECCs. The results revealed that is possible to design a sustainable ECC with high ductility and optimized mechanical strengths with the use of LC3, especially at FA/LC3 ratios of 0.8 and 1.2. Importantly, at all FA-to-LC3 ratios, the chloride permeability results of LC3-ECCs were more than two times lower than that of the control OPC-ECC.