Development of engineered cementitious composites containing iron ore tailing powders

The substitution of iron ore tailing powders(IP) for fly ash as mineral admixtures was studied in the development of engineered cementitious composites(ECC). The focus was placed on the effect of IP content on the tensile properties and compressive strength of ECC. The mechanical properties of ECC with IP were also compared with those of traditional ECC with fly ash. Experimental results show that it is feasible to use IP as mineral admixtures to produce high-ductile ECC. ECC with IP exhibits a lower strength performance but a higher ductility under tensile load than ECC with fly ash at the same addition of mineral admixtures. ECC with an IP/cement mass ratio of 1. 2-2. 2 shows a 28-d compressive strength of 36. 7-54. 2 MPa,which meets the compressive strength requirement of normal concrete structures,and a 28-d tensile ductility of 3. 4%-4. 3%. The amount of iron ore tailings in those mixtures accounts for 66. 6%-77. 0% of the total solid matrix ingredients of ECC.