Upgrading the compressive strength and radiation shielding properties of high strength concrete supported with nano additives of lead monoxide and granodiorite

The current study aims to enhance several properties of high-strength concrete (HSC) by incorporating two distinctly classified and inherently different nanomaterials into the concrete matrix ingredients. Nano-lead monoxide (NL), known for its high density and radiation attenuation capability, and nano granodiorite powder (NG), as a promising supplementary cementitious material (SCM) with pozzolanic activity ,were individually investigated at increasing replacement ratios of cement weight up to 5%. Additionally, an optimized mix containing the optimal replacement ratios of both materials was designed to maximize the concrete shielding capacity against radiation penetration. The NL/NG concrete was analyzed using XRF, XRD, SEM, and EDX techniques. The radiation shielding assessment of the examined NL/NG-concrete mixes were evaluated using the Monte-Carlo simulation and Phy-X software. Results showed the ability of NG to improve the compressive strength of HSC, where the optimum replacement ratio was 4%, with an increase of 17.3% compared to the control mix. This improvement was at lower rates in the case of NL, where a 3% replacement ratio resulted in a 7.96% increase in compressive strength before the strength value declined at higher replacement ratios. For the other properties, increasing the replacement ratio of NL in the concrete mix leads to a delay in setting times and an increase in workability, accompanied by a decrease in consistency. On the other side, the incorporation of NG into the concrete exhibited the opposite effect on all the properties above. The combined mix of 5%NL+4%NG led to an 11.7% enhancement in the compressive strength value with improved overall concrete performance, especially its radiation shielding property. The studied NL/NG-concrete samples provide the best protection against gamma-rays. Lastly, the excellent performance of the mixes of NL and NG on HSC would pave the way for their employment as radiation shielding in various nuclear and medical facilities.