Development of ultra-high ductility engineered cementitious composites as a novel and resilient fireproof coating

Fireproof coatings are essential for the fire safety of steel structures. A major disadvantage of conventional cementitious fire-resistive material (CFRM) is the susceptibility to crack or delamination from the steel substrate under the combination of fire and loading due to its brittleness. Unlike brittle CFRM, ultra-high ductility engineered cementitious composites (ECC) holds promise to increase the cohesion between coating and steel substrate. The objective of this research is to develop a lightweight ECC as a novel and resilient fire-resistive engineered cementitious composites (FR-ECC). The tensile and compressive properties, dry density, bonding strength, and thermal conductivity of FR-ECC were systematically investigated. The cohesive performance between FR-ECC and steel substrate was determined by reversed flexural tests. The FR-ECC specimens exhibit robust strain-hardening performance in tension as well as large deformation capacity in compression due to the fiber-bridging effect. FR-ECC demonstrates lower bond strength but superior integrity with steel substrate compared to those of CFRM. The successful development of FR-ECC lays the groundwork for its future application in protecting the steel structures under fire.