Shielding and strength tests of silica fume concrete

In this research, concrete containing different percentages of lead powder and silica fume was investigated as a gamma shield. Gamma photons emitted from gamma sources of 137Cs and 60Co were passed through concrete specimens and detected by two inches NaI(Tl) detector to investigate the attenuation coefficients of the specimens. Next, the compressive strengths of the specimens were experimentally studied. A comparison of concrete with and without silica fume revealed that although the addition of silica fume results in a slight reduction of the attenuation coefficient, which is negligible, it increases the compressive strength of concrete significantly. The results suggest the usefulness of 15% silica fume in concrete containing lead as a gamma shield.

► By increasing silica fume, the resistive strength of concrete increased.
► The linear attenuation coefficient rate decreases to 2.9% with a 137Cs source.
► Adding of 15% silica fume in concrete with 45% lead increases the strength to 22%.