Mechanical and radioactivity shielding performances of mortars made with colemanite, barite, ground basaltic pumice and ground blast furnace slag

• All building materials contain more or less natural radioactivity.
• The concrete strength at later ages has increased significantly by using blast furnace slag.
• Linear absorption coefficient decreased with increasing colemanite ratio.
• Barite, colemanite and blast furnace slag wastes are effective to prevent radiation transmission.
• They seem to be promising materials for gamma ray shielding in mortars.

All building materials contain more or less natural radioactivity. The present paper reports the results of an experimental study on the mechanical and radiological aspect of the use of colemanite, barite, ground basaltic pumice and ground blast furnace slag as additives in the production of special mortars. The results show that the compressive and flexural strengths of the mortars at later ages has increased significantly by using blast furnace slag as an additive. However, the compressive strength was lower than those of the reference samples for all the samples with different additive percentages of pumice and barite for all ages. Linear absorption coefficient decreased in samples with colemanite additive with increasing colemanite ratio. From the linear absorption experiments, increases in the coefficient were observed in the samples with blast furnace slag at the beginning, but opposite effect starts for values higher than 2.5%. Mortars with colemanite and blast furnace slag had low radioactive permeability. These samples should be preferred for places which are exposed to radioactive effect.The linear absorption coefficients of samples with 5% pumice additive were very near to those of the samples with barite additive. Hence pumice may be used in regions where radiation is effective. It can easily be used in walls and coverings of medical buildings and nuclear reactors.

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