Performance of engineered cementitious composites under-elevated temperature--a review

Concrete is known for its strength and durability, but its performance under high temperatures is often compromised due to its brittle nature. Engineered Cementitious Composites (ECC), also known as bendable concrete, show due to their strain hardening with multiple cracking behaviour. ECC has been proven effective in applications such as repair, rehabilitation, bridge decks, and seismic activities. The performance of the structures under fire is a crucial aspect as it loses its strength irrespective of the material used, because with the increase in temperature, it loses its strength and stiffness, making fire resistance a critical concern. The fibers used in ECC play an important role during fire scenarios due to their fiber-bridging property. This can be fulfilled by using several types of fibers to enhance the overall performance of ECC. After reviewing various studies, the findings show that to achieve required workability, the ECC mixshould have low yield stress and high plastic viscosity. This paper reviews the effect of elevated temperature on the mechanical properties of ECC, focusing on compressive, tensile, and flexural strength, and explores the role of fiber bridging in enhancing fire resistance. The strength was increasing then decreasing, due to thermal bridging property. Spalling was reduced due to pore pressure release through the pores created after fiber melting. The failure mechanisms of the fibers, including fiber rupture and pull-out out were observed from SEM images. Additionally, microstructural analysis is discussed to understand the fiber-matrix bonding.