Mechanical Properties and Permeability of Heavyweight Concrete Containing Iron Pellets, Crumb Iron, and Microsilica

Concrete that has higher specific gravity than conventional concrete is known as heavy concrete. The use of high specific gravity aggregate is the most important way for the production of heavy concrete. Due to the use of aggregates with metallic properties and high atomic number, this type of concrete has the property of shielding against harmful rays. In this research, the possibility of using iron pellets with crumb iron as a substitute for concrete aggregate to produce heavy concrete has been investigated. For this purpose, 25, 80 and 100% of aggregates have been replaced with pellets and iron shells, and to prevent the effect of this replacement on increasing the porosity of concrete, part of the mixing cement has also been replaced with micro silica. Compressive strength, tensile strength, flexural strength as well as permeability tests have been performed on the constructed specimens and the specific gravity of the produced heavy concrete has also been reported. The results show a very good effect of micro silica on improving the properties of heavy concrete. The compressive strength of heavy concrete in the presence of micro silica is up to 34% higher than conventional concrete. Tensile and flexural strengths have increased up to 50% and 12%, respectively, compared to conventional concrete if micro silica is used, respectively. The permeability of heavy concrete for each percentage of pellet and iron shell replacement was lower than conventional concrete