Durability of engineered cementitious composites under extreme conditions

Abstract

Applying conventional concrete materials in civil infrastructures can result in structural failure due to their high rigidity, posing significant risks to human safety. As a result, engineered cementitious composite (ECC) has emerged as a feasible solution to address the issues due to their exceptional mechanical properties, tension strain-hardening, thermal resistance, impact resistance, seismic resistance, high durability, ductility, and environmental sustainability for various applications in civil infrastructures such as high-rise buildings, tunnels, motorways, bridges, defense structures, secure enclosures, and containment vessels for hazardous materials. However, the durability of ECC can be compromised under harsh conditions, raising significant concerns about its reliability, stability, and efficiency. Therefore, this study reviews the durability of ECC under extreme environmental and loading conditions. The study shows that elevated temperatures adversely impact the mechanical properties of ECCs, leading to microstructural changes and potential durability issues. Additionally, ECCs are susceptible to degradation, corrosion, and dimensional changes in corrosive environments, excessive humidity, and de-icing conditions. Freeze-thaw cycles and alkali ingress through micro-cracks can also compromise the durability and microstructure of ECCs. The study further shows that ECCs experience dimensional instability and reduced mechanical strength under extreme deep-sea pressure conditions, while low-pressure or vacuum environments can lead to outgassing and thermal cycling effects. ECCs are prone to fatigue, fractures, and deformation under mechanical stress due to vibrations, shocks, and collisions. On the contrary, ECC enhances the resilience of beam-to-column connections under cyclic loading, potentially improving seismic resilience in high-risk earthquake areas. Substituting reinforced concrete structures with ECC can boost seismic response and reduce post-earthquake restoration needs, requiring less shear reinforcement and maintenance. The review includes that ECC outperforms plain mortar and conventional self-consolidating concrete in impact resistance, showing controlled cracking and extensive surface indentations before failure. Although ECC can be susceptible to some extreme conditions, its superior durability compared to standard concrete in challenging environments positions it as a viable choice for diverse applications in civil infrastructure. Lastly, advances in durability-improving techniques of ECC are summarized, and future directions with concluding remarks are provided.