Determining the appropriate ratio of fly ash as cement replacement in concrete and evaluating the radiation dose of the fly ash concrete

This study uses fly ash (FA) as a cement replacement in concrete and evaluates the radiological safety of this concrete sample. Different fly ash mixing ratios were investigated and found that with a mixing ratio of 35%, the compressive strength of FA concrete is the highest (from 38 to 48 MPa). Next, we evaluate the radiation safety of the FA concrete by analyzing the isotopes 226 Ra, 232 Th, and 40 K using two low-background gamma spectrometers. The obtained results showed that the use of FA in concrete production is entirely feasible as it meets both construction and radiation safety-related requirements.