Gamma radiation attenuation, mechanical properties and microstructure of barite-modified cement and geopolymer mortars
Daria Jóźwiak–Niedźwiedzka, Pavel Rovnanı́k, Mariusz Dąbrowski, Jakub Ośko, Michał Kuć, Maciej Maciak
Abstract
The present study contributes to the development of alternative materials for radiation shielding, focusing on environmental sustainability and material cost efficiency. The primary aim was to evaluate the compressive and flexural strength, mineral composition, microstructure, and gamma-ray attenuation properties of cement mortars and geopolymer mortars containing barite powder. Mortars based on ordinary Portland cement (OPC) and fly ash geopolymers with varying amounts of barite powder were assessed for their shielding properties at energy levels associated with the decay of 137 Cs. From the results, key parameters such as the linear attenuation coefficient (μ), mass attenuation coefficient (μ m ), half-value layer (HVL), and tenth-value layer (TVL) were determined. The results showed that while cement-based composites exhibited superior gamma radiation attenuation compared to fly ash geopolymer mortars, the latter had higher mass attenuation efficiency, meaning less material density was required for the same level of shielding. Additionally, cement mortars had 23–25 % higher mechanical strength than geopolymer mortars. Importantly, the inclusion of barite powder improved the radiation shielding performance of both materials by 7–10 %, demonstrating its effectiveness in enhancing the protective properties of these mortars. This research highlights the potential of fly ash geopolymer mortars as viable, eco-friendly alternatives to traditional cement mortars in radiation shielding applications. • Cement mortars exhibited higher linear attenuation, HVL, and TVL than geopolymer mortars. • Barite enhanced shielding more in cement mortars compared to geopolymer mortars. • Fly ash geopolymer mortars had higher mass attenuation, offering better shielding per unit mass. • Geopolymer mortars showed lower strengths than ordinary Portland cement mortars. • Barite substitution did not affect the microstructure of either mortar type.