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Geopolymer has become a viable, eco-friendly, and effective alternative to Portland cement as binders in concrete meant for structural engineering and radiation shielding purposes. However, the radiation interaction cross-section of geopolymer could be lower than that of cement due to differences in chemical compositions. In this study, the influence of B4C on the strength and nuclear-radiation interaction parameters of kaolin-based geopolymer was investigated. Calcined kaolin and NaOH was used as the precursor and alkali activator in the preparation of the geopolymer, respectively. The pristine geopolymer was mixed with 15% B4C by weight. The density and compressive strength of the geopolymer paste were determined after curing for 24 hours at 80 °C. Gamma photon, thermal, and fast neutron interaction parameters were computed using standard empirical expressions and cross-section data library. The addition of B4C increased the bulk density and compressive strength of the geopolymer paste from 2.06 to 2.18 g/cm3 and 5.14 to 13.41 MPa, respectively. In addition, the flexural strength and modulus of expansivity increased when B4C was introduced into the geopolymer. The radiation interaction parameters changed differently for photons and neutrons. Although there was a decrease in the mass attenuation coefficients of gamma photons with energies within 0.015-3.00 MeV after B4C was introduced in the geopolymer matrix, the decrease was however insignificant. The macroscopic total cross-sections for fast and thermal neutrons increased from 0.0711 cm-1 to 0.0817 cm-1 and 0.2174 cm-1 to 10.9145 cm-1, respectively. Boron-carbide can be used to enhance the strength and shielding efficacy of geopolymers.
| Abstract Category | Materials Physics |
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