Effect of Nano-ferrite addition on mechanical properties and gamma ray attenuation coefficient of steel fiber reinforced heavy weight concrete

Perfect pure Nano-ferrite (NF) powder with 29.6 nm particle size was prepared using citrate-gel method and added with (1 and 2)% of binder to barite concrete mixes incorporating 450 kg/m(3) cement content, 15% silica fume (SF) of particle size (1 gm) as a cement replacement. Steel reinforced fibers (SRF) of hooked shape with specific gravity of 7.85, diameter of 1.12 mm, aspect ratio of 22.3 and strength of 1100 N/mm(2), were added with (0.5, 1 and 1.5)% of concrete total volume. Their effects on mechanical properties, microstructure, gamma-ray attenuation coefficient (mu) and density were studied. All studied properties of mixes were improved using SFR and NF with increasing their percentages. The best results were obtained using 2% NF. The improvements of this mix with respect to the control mix at 7 and 28 days ages compressive strength were 71% and 66%, respectively while the splitting strength, mu of (Co60-1332.5) and density improvements were, 101%, 138.5% and 2.5%, respectively at 28 days age. (C) 2019 Elsevier Ltd. All rights reserved.