Investigation of the Compressive Strength of Heavy Concrete Made with Locally Sourced Barite Aggregates

Concrete is the material mostly used for radiation shielding and to a large extent, the quality of it depends on aggregate used to produce it. This is a report on investigation carried out on one of the aggregates used to produce heavy concrete used for radiation shielding. Barite aggregates were locally sourced from 2 states. Using British Standard, these samples were subjected to apparent specific gravity, Bulk density, Void ratio, Sieve analysis, absorption capacity and moisture content tests. Thereafter a concrete of nominal mix 1:2:4 using W/C ratio of 0.65 was used to prepare 3 types of concrete cubes of 150 150 150 mm, A, B and C. A total of 135 cubes were produced for the 3rd, 7th, 14th, 21st and 28th day s test so that each type of sample has 45 cubes. Fresh concrete was subjected to workability test while the hardened concrete samples were subjected to density and compressive strength test. Test results show that the specific gravity of the 2 heavy aggregates are the same -4.2, while granite has 2.63; the bulk density of aggregates from Azara, Lesse and Zania are 2523.8, 2509.7 and 1563.2 kg m-3 and absorption capacity are 1.84, 2.35 and 5.83, respectively. The slump value for the samples A, B and C are 101, 109 and 42, respectively. The compressive strength of samples after 28 days of curing are 21.16, 21.04 and 17.60 N mn 2. Based on the results of investigation, it was concluded that the quality of concrete produced using locally sourced barites is better than the one made of granites. In addition, our local barites can be used as aggregates for producing heavy concrete, used for shielding nuclear radiation. It was, however recommended that the nuclear attenuation characteristics of concrete made of such aggregate should be investigated. In recent times, human activities have introduced new sources of radiation such as X-rays used in medicine, nuclear weapons and nuclear reactors for power generation. These pose risks as such research effort to find solution to such problem like radiation shield will assist most especially with the recent commissioning of nuclear reactor in Nigeria. Besides, too much pressure is put on granite and gravels for the production of concrete, this can be a right step in solving this problem.