Rheological and Mechanical Properties of Heavy Density Concrete Including Barite Powder

Abstract

Heavy weight concretes (HWCs) or heavy density concretes are commonly used for radiation shielding in nuclear plant to ensure protection against X-rays and Gamma rays. It can also be required in other structures where a large mass is needed. This experimental study was effected to design a HWC, which can be used in bentonite-bored piles concreting in order to remove as much as possible the amount of mud that resides in the pile. In this study, barite is used as fine aggregate mixed with Portland cement to design HWC. Different barite concrete mixes were designed, where barite is used once as an addition while maintaining constant the amount of cement (400 kg/m3) and as a substituent, with different percentage (38, 46, 53 and 57%) to reach different concrete densities. The effect of barite on rheological, heat hydration and mechanical behavior of concrete was investigated. The use of barite as an addition leads to an increase in viscosity and yield stress of concrete; however, when barite is used as a cement substituent, a viscosity decrease is recorded. Barite concrete has shown a lower heat of hydration generation in comparison with a standard mix, which is correlated with compressive strength results.