Effects of nano titanium and nano silica on high‐strength concrete properties incorporating heavyweight aggregate

Abstract

Abstract This investigation aims to study the effect of replacing 100% of fine and coarse aggregates with heavyweight aggregates and adding nano titanium (NT) and nano silica (NS) on shielding against radiation and on the mechanical and transport properties of heavyweight high‐strength concrete (HWHSC). In this study, 20 mixes were prepared that included the use of hematite and steel slag (SS) aggregate with NS or NT used as additions to mixes by the ratio 1% and 3% from cement weight. To study the effect of the total replacement of aggregates and the addition of nanomaterials (NMs) on the properties of HWHSC, to study engineering properties the slump, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity were applied. Density, chloride permeability, sorptivity coefficient, water permeability, and microstructure tests were also performed. To study the efficiency of shielding against radiation, linear attenuation coefficient, mass attenuation coefficient, mean‐free path, half‐value layer, and tenth‐value layer of different gamma‐ray sources of radiation 137Cs 662 (keV) and 60Co 1332 (keV) were applied. The results showed that the 100% SS and hematite replacement as coarse and fine aggregates with 3% (NS or NT) achieved the best mechanical and transport properties compared to other mixtures. While the highest density of the string containing hematite and SS was achieved with 3% of NT, with a density of 3384 kg/m 3 . The highest compressive strength of more than 116 MPa was achieved for the included mixture of 3% NS. The highest attenuation of gamma‐ray radiation was achieved with the application of hematite and SS aggregates with 3% of NT.