| Experimental investigation of strength, durability, and microstructure of red‑mud concrete |
Chava Venkatesh
, Ruben Nerella, Madduru Sri Rama Chand |
| Department of Civil Engineering, Vignan’s Foundation for Science, Technology and Research, Guntur, Andhra Pradesh, India |
|
|
|
Received: November 5, 2019; Revised: November 28, 2019 Accepted: November 29, 2019. Published online: February 29, 2020. |
|
|
|
| ABSTRACT |
|
Recent trends in the construction industry involve the use of industrial by-products as building materials to improve waste management and reduce excessive CO2 emissions from the cement industry. Red mud (RM) is a by-product of alumina refinery plants. When improperly disposed, red mud harms the surrounding area, owing to its highly alkaline nature. In the current work, up to 15% of the cement in concrete was replaced with red mud, in increments of 2.5%. In addition, to enhance the pozzolanic reaction, metakaolin was used as a ternary mineral; it replaces 10% of the cement. A slump cone test was conducted to evaluate the workability. Compressive, flexural, and split tensile strength tests were conducted to observe the mechanical properties. A rapid chloride penetration test and water absorption tests were conducted to determine the durability properties of the concrete. X-ray fluorescence analysis was conducted to determine the chemical composition of both the red mud and the metakaolin. A scanning electron microscope analysis was conducted to characterize the microstructure of the RM concrete. The 12.5% red-mud replacement mix showed the greatest improvement in mechanical properties among all the mixes. As the red-mud replacement increased, the chloride-ion passage was reduced. Moreover, a denser microstructure formation was observed with the red-mud replacement, as compared to standard concrete. |
| Key words:
Scanning electron microscope · Mechanical properties · Metakaolin · Rapid chloride penetration test · Red mud · Split tensile strength |
|
|
|
PDF Links 
Full text via DOI
Download Citation 
