Barite powder as sand substitution in concrete: Effect on some mechanical properties

• The effect of sand substitution by barite powder on concrete has been examined.
• Limestone skeleton should be conserved to reduce the compressive strength loss.
• The use of barite induces a reduction of elasticity modulus around 20%.
• Replacing sand by barite reduces the tensile strength of concrete to half.
• Barite powder does not affect the concrete swelling but reduces shrinkage.

Barite (BaSO4) is a mineral commonly used as aggregates to produce heavyweight concrete. The applications concern radiations shielding in hospitals and nuclear facilities. In this work, the use of Tunisian barite powder form in the composition of concrete was investigated, substituting sand partially or totally. Investigation was carried out on five groups of concrete samples with density (2.31–2.48) corresponding to the mass of barite’s percentages ranging from 0% to 25%. The effect of barite ratio on the physical and mechanical properties such as compressive strength, tensile strength, density, shrinkage, swelling, and elastic modulus have been measured and compared to ordinary concrete as a control. Although the tensile strength has been reduced up to 50%, it has been shown that is possible to produce a barite-based concrete with a minor effect on the main mechanical parameters: the compressive strength at 28 days has decreased only by 10% and the elastic modulus at one year of age by 20%. This was possible by conserving the initial limestone skeleton and using barite in size (0–100 μm). The new designed mixture containing barite in powder form can be used for structural concrete.