Utilization of Iron Ore Tailing in Controlled Low-Strength Material- Development and Characterization
摘要
Construction industry is prioritizing sustainability in infrastructure development and there is a significant demand for incorporating industrial waste into civil engineering applications. Iron ore tailing (IOT) is a mining waste generated during beneficiation of iron from its ore. In the present study, iron ore tailing and fly-ash based Controlled Low-Strength Material (CLSM), is developed, and characterized for its fresh and hardened properties. Mix proportions were developed and tested for bleeding, density, flowability, and unconfined compressive strength. Specific mixes were tested for engineering properties namely California bearing ratio (CBR), permeability, and shear strength. Further mineralogical and microstructural characteristics of CLSM were analyzed. IOT is classified as a poorly graded sand with silt, having a friction angle of 49° and leaching studies revealed IOT is environmentally safe. For the design of IOT based flowable fill for structural fill applications, a mix design range is proposed. The unconfined compressive strength of CLSM specimens ranged between 0.98 and 3.3 MPa for mixes with flowability between 200 mm and 300 mm. The permeability of IOT based CLSM is in the order of 10− 5 cm/sec. CBR value of CLSM mix ranged between 83% and 159%, making it suitable for subgrade and subbase applications. Mineralogical and microstructural analysis indicate that the addition of IOT does not hinder the hydration process as well as formation of hydration compounds, thereby enhancing the strength of CLSM. The present research affirms that, CLSM can be designed with satisfactory properties by incorporating up to 65% IOT in the mix.