Valorization of hazardous chrysotile by H3BO3 incorporation to produce an innovative eco-friendly radiation shielding concrete: Implications on physico-mechanical, hydration, microstructural, and shielding properties

For the first time, the hazardous chrysotile was valorized as an aggregate in radiation shielding concrete (RSC). This was accomplished through its amalgamation with two different ratios of boric acid (H3BO3) by 1 and 3% of cement mass to produce CR1, and CR2 concrete mixtures, respectively, in comparison with zero H3BO3 in the control concrete (CC). Physico-mechanical, hydration, and microstructural properties of these concrete mixtures were analyzed employing X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), X-ray fluorescence (XRF), scanning electron microscopy (SEM), thermogravimetry/its derivative (TG/DTG), and physico-mechanical tests. Additionally, the radiation shielding was evaluated using Pu-Be, and 60Co sources. Computational studies using NXcom, and WinXCom, as theoretical calculation programs accompanied by the MCNP-5 code as a simulation tool, were applied to verify the radiation shielding measurements. The findings showed that the CC has reasonable radiation shielding with acceptable physico-mechanical properties. On the contrary, CR1 and CR2 had deleterious mechanical and microstructural properties, but more enhanced neutron shielding properties compared to their precursor CC. This conclusion was verified by the remarkable compati-bility between the computational and experimental outcomes. Ultimately, H3BO3 additions boosted the radiation shielding of chrysotile concrete despite their devastating impact on the mechanical and microstructural prop-erties, emphasizing the eligibility of chrysotile as an aggregate in RSC.

Automated summary

In this study, the hazardous chrysotile was used as an aggregate in radiation shielding concrete for the first time. The addition of boric acid was found to enhance the neutron shielding properties of the chrysotile concrete, although it had detrimental effects on the mechanical and microstructural properties. Computational and experimental results were in good agreement, confirming the suitability of chrysotile as an aggregate in radiation shielding concrete.