Elevated temperature effects on the compressive strength and radiation shielding capability of waste granite and marble concrete

Abstract

In an effort to promote the development of sustainable construction practices, this study explores the utilization of construction waste powders as partial cement replacements in concrete. Specifically, granite and marble waste powders were incorporated at varying replacement ratios up to 9% by cement weight. The influence of these waste materials on the compressive strength and radiation shielding effectiveness of ordinary concrete was evaluated under both ambient and elevated temperature conditions (up to 800 °C). The findings revealed significant enhancements in the mechanical properties. Notably, 9%  cement replacement ratio with waste granite powder (WGP, 9G) yielded the optimal performance for compressive strength, exhibiting increasements of 25.6% and 33.2% at room temperature and 800 °C, respectively. Similarly, a 5% replacement ratio with waste marble powder (WMP, 5M) demonstrated moderate improvements, achieving gains of 10.3% and 18.7% in compressive strength at room temperature and 800 °C, respectively. The samples at optimal replacement ratios of 9% and 5% for granite and marble, respectively, were tested alongside the control sample (CO) to study their effectiveness in attenuating the various types of radiation. The radiation shielding assessment was evaluated against gamma and neutron using the MC Monte Carlo simulation-5 algorithm and Phy-X software. The  gamma ray linear attenuation for concrete mixes (\(\text{CM}\)_LAC) order for the CO group was found to be CO < 400CO < 600CO < 800CO. The \(\text{CM}\)_LAC order for the G9 group is G9 < 400G9 < 600G9 < 800G9. The \(\text{CM}\)_LAC order for the M5 group is M5 < 400M5 < 600M5 < 800M5. The neutron performance (FC) of the CM-concrete samples has values 0.079, 0.075, 0.071, and 0.067 cm⁻¹ for CO, 400CO, 600CO, 800CO samples, 0.094, 0.090, 0.085, and 0.080 cm⁻¹, for G9, 400G9, 600G9, 800G9 samples, and 0.089, 0.083, 0.079, and 0.074 cm⁻¹, for M5, 400M5, 600M5, 800M5 samples, respectively. Thus, the studied CM-concrete samples at room temperature provide the best protection against gamma and fast neutrons. Exposure to high temperatures significantly reduced the gamma and neutron attenuation of concrete samples. However, mixes with optimal granite and marble waste replacements showed enhanced resistance  to this effect compared to the control mix.