Experimental Study on Ultra-lightweight Fire-resistive Engineered Cementitious Composite

A special material, ULFR-ECC (Ultra-lightweight fire-resistive engineered cementitious composite), is introduced as a new kind of fire insulation. As a special member in the family of ECC (engineered cementitious composites), ULFR-ECC with a dry density of 566kg/m(3) possesses the characteristics of strain hardening, ultra-ductility and also those in normal fire retardant coating, like lightweight and thermal insulation. Used as fire insulation on steel structure, ULFR-ECC may solve the existing issues of normal non-bulgy inorganic fire insulation, like debonding and dropping off at high stress condition or under earthquake impact. This paper presents the process of producing ULFR-ECC, including the mix proportions and mixing & curing. Additionally, the physical and mechanical properties of ULFR-ECC with 3 different poly-vinyl alcohol fiber volume fractions were experimentally studied. The test results indicate all the tested ULFR-ECCs exhibit multi-cracks and strain hardening both under tension and compression. The strain corresponding to the peak tensile strength reached 2.17%, 2.73% and 2.81%, and the strain to the 80% of peak compressive strength reached 1.95%, 1.83% and 2.24%. Owing to the superior mechanical property, ULFR-ECC makes a new solution for the sustainability of fire insulation of steel structure.