Alternative binder materials in ECC—a review

Engineered cementitious composites (ECCs) or strain-hardening cement-based composites (SHCCs) are a particular kind of high-performance fibre-reinforced concrete (FRC) developed in the late 1990s. Owing to the unique matrix tailoring employed in its development, it does not show the brittleness associated with conventional concrete, However, this also means the elimination of coarse aggregate. This factor along with the requirement of low water–cement ratio would mean the use of high volumes of cement. Cement incurs the highest cost among the materials used in ECC after fibre. While the use of alternate fibres makes it difficult for the composite to achieve its strain- hardening properties, alternate binder materials have been successfully adopted for ECC. The carbon footprint involved during cement production also necessitates the study and use of complementary materials. This paper discusses alternate substitutes for the various binder and filler materials often employed in conventional ECC. The roles of each component are described before alternatives are suggested. This paper discusses the availability of different alternate binder materials and their influence on the properties of ECCs, with reasons behind the same. Materials such as fly ash, slag, silica fume etc., are discussed in detail along with binders such as volcanic ash and waste ceramics. In the end, the scope of ECC as a pavement material is discussed, with the suitability of alternative binders for the same.