Densification of concrete using barite as fine aggregate and its effect on concrete mechanical and radiation shielding properties

الملخص EN

This paper presents findings of research conducted on the improvement of radiation shielding in concrete, using barite as fine aggregate.

Barite is a heavy mineral, having specific gravity in range of 3.5 to 4.5, and is abundantly available in different parts of Pakistan.

Radiation shielding of barite concrete was studied experimentally for use in optimization of the thickness of radiation therapy bunkers.

The Influence of barite on mechanical properties of concrete was also studied for a range of water-to-cement ratios from 0.30 to 0.45.

ASTM standards were used to compute compressive and tensile strengths of concrete, whereas thermogravimetric analysis was carried out to determine percentage weight loss at elevated temperature.

Radiation shielding potential of concrete was studied by subjecting concrete sections to gamma-ray source (Cobalt-60).

Experimental results showed that the use of barite mineral as fine aggregate increases shielding ability of concrete.

Linear attenuation coefficient was found to increase by 28.4% and varied proportionally with the variation in density of concrete.

However, a slight decrease in compressive and tensile strengths was noted with the addition of barite as fine aggregate concrete.

Due to high absorption capacity of barite, the problem of workability was overcome through the use of admixtures within allowable limit of ASTM (i.e., less than 3%).

Finally, an optimum water-to-cement ratio of 0.45 for barite mineral infused concrete is recommended for the least reduction in mechanical properties and with significantly improved level of radiation shielding.