ENVIRONMENT
 

UTILISATION OF KUDREMUKH IRON ORE TAILINGS FOR FINE AGGREGATE IN CONCRETE AND MORTARS

 

Principal Investigator

:

Prof. B. V. Venkatarama Reddy

Co - Investigator

:

Mr. H. Hemanth Kumar

Budget

:

Rs. 18,62,400/-

Duration

:

Three years

 

The main objective of the project is to investigate the suitability of Kudremukh Iron Ore tailings as a substitute for sand in mortar and concrete applications in the construction Industry. The following studies were proposed to meet the project objectives.

  • Characterising the physical and chemical properties of iron tailings.

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  • Characterising the properties of mortars in fresh and hardened state using iron ore tailings and comparing with the properties using standard sand. The tests planned on mortars include workability, drying shrinkage, water retentivity, strength and stress-strain characteristics.

    •

  • Determination of bond strength (adhesion) and compressive strength of masonry using mortar with iron ore tailings. Burnt clay bricks as well as concrete blocks will be used for these studies.

  • Characterising the properties of concrete using iron ore tailings as fine aggregates. Workability, shrinkage, strength and stress-strain characteristics of concrete will be examined.

  • Monitoring the properties of mortars as well as concrete using iron ore tailings as fine aggregate over a period of at least two years to throw more light on long-term performance.

  • Construct a demonstration building using mortar and concrete made from the iron ore tailings.

  • Conducting an exposure programme for the building professionals on the use of iron ore tailings for mortar and concrete applications.

Salient research achievements:

Apart from collecting the large quantities (~20 tonnes) of tailings samples from the Kudremukh Iron Ore Company limited at Kudremukh, the following R&D work is completed.

(a)   Characterization of the physical properties of the iron ore tailings

(b)   Flow characteristics of mortars using ore tailings

Observations:

  1. Coarse sand fraction is totally absent in the iron ore tailing samples. Medium and fine sand present is more than the silt fraction in all the samples. A small amount of clay size fraction (1 - 4%) in tailing samples is present. The specific gravity of the tailing samples varies between 2.77 and 3.35.

  2. Flow versus water-binder (W/B) ratio is linear. Flow increases with increase in W/B ratio. Maximum flow value is achieved for 25% sand replacement by the tailings in all the 12 mix proportions attempted.

  3. The mortar shrinkage is minimum at 25% iron ore tailings for all three grades of mortars and is maximum for 100% tailings substitution.

  4. Iron ore tailings can be successfully used for mortars in masonry and renderings.

  5. Leachability, durability, shrinkage and long term strengths are being studied for making final recommendations.

 
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