Performance of engineered cementitious composites containing high volume of ceramic powder and magnetized water

Abstract

Engineered cementitious composites (ECC) is a promising type of ultra-high-performance concrete with improved ductility, high tensile strain-hardening, and multiple-cracking characteristics. It can withstand tensile strains of over 3-5% while containing a relatively low fiber fraction of less than 2% by volume. Sustainability of ECC has become a pressing concern due to its high content of cement that releases huge amount of carbon dioxide (CO 2 ) in its production. In this study, seven mixes were designed and tested to evaluate the performance of ECC containing a high proportion of ceramic powder (CP) as cementitious materials partial replacement, and magnetized water (MW) as ECC mixing water. The CP was used with four different ratios, namely, 20%, 40%, 60%, and 80%. The effect of using MW instead of tap water (TW) was measured on ECC mixes containing 0% and 20% CP. The MW was prepared using a permeant magnetic field of 1.6 Tesla. Several fresh and hardened properties of ECC mixtures were measured, including workability, compressive strength, and water absorption. Microstructure analyses were also conducted on selected ECC mixes to closely investigate the effect of the applied variables. The results reflected significant improvement in ECC workability when using CP or MW by up to 20%. A gradual decrease in ECC compressive strength with increasing the content of CP by up to 80% was reported. Using MW instead of TW slightly improved ECC compressive strength at 7 days by 2%, but the strength deceased at later age of 28 days by up to 5%. It was also found that the water absorption rate of ECC increased while the corresponding compressive strength decreased.