Work

Effect of tailing powder content on dynamic behavior of iron tailing porous concrete: An experimental study

Year: 2024

Type: article

Abstract: Iron tailing porous concrete (ITPC) is a new type of green-engineered composite that uses iron ore tailing (IOT) powder to partially replace cement in conventional foamed concrete. This study investigates the dynamic properties of ITPC with a range of IOT content (15 % to 35 %) under high-strain rate loads, as well as the hydration products and microstructures of ITPC. Additionally, foamed concrete specimens without IOT powder are prepared and tested as references. The X-ray diffraction (XRD) results indicate that the addition of IOT powder causes the presence of iron oxide (Fe 2 O 3 ) and silicon dioxide (SiO 2 ) in the ITPC, resulting in a decrease in calcium silicate hydrate (C-S-H) gel and ettringite (AFt). A split Hopkinson pressure bar (SHPB) facility is used to perform impact tests at expected strain rates from 120 to 250 s −1 . The experimental results demonstrate that the properties of ITPC obtained in dynamic loading tests exhibit significant IOT content dependence and strain rate effects . Moreover, scanning electron microscopy (SEM) analysis reveals that excessive IOT content results in the formation of numerous micro-cracks and loose pore structures within the ITPC specimens. ITPC with IOT content ranging from 25 % to 30 % achieves the optimal performance with high impact resistance and effective utilization of iron tailing waste. Specifically, at the expected strain rates of 120, 200, and 250 s −1 , increasing the IOT content from 15 % to 35 % resulted in reductions of compressive strength by 37.52 %, 51.34 %, and 51.22 %, respectively. The corresponding dynamic increase factors of ITPC achieved the maximum values of 1.25 (25 % IOT content), 2.16 (30 % IOT content) and 3.12 (30 % IOT content), respectively.

Source: Case Studies in Construction Materials

DOI: 10.1016/j.cscm.2024.e03635