Recycling E-waste CRT glass in sustainable geopolymer concrete for radiation shielding applications

Waste cathode ray tube (CRT) glass, enriched with heavy metal of Pb, is classified as hazardous waste and needs to be disposed of harmlessly. This study recycles waste CRT glass as heavy aggregate in sustainable geopolymer concretes (GCs) to enhance its γ-ray shielding performance. It also comprehensively evaluates its macro-performances, microstructure, and environmental and economic impacts. The results demonstrate that the compressive strength of GCs decreases with the dosage of CRT glass. The generation of geopolymer gel is hindered by excessive CRT glass. Besides, the compatibility between CRT glass and the geopolymer matrix is poor. Both factors influence the strength development of CRT glass-incorporated GCs. The compressive strength of GCs with 50 % CRT glass aggregate exceeds 30 MPa, meeting the requirements for building materials . Due to the increase in the density and the introduction of heavy nuclei Pb, the γ-ray shielding performance of GCs is 9 % higher than that of normal concrete. In terms of economic and environmental benefits, this approach realizes the value-added recycling of CRT glass, avoiding the disposal cost of CRT glass. Besides, due to the utilization of sustainable geopolymer as cementitious materials , the carbon footprint of designed CRT glass-enhanced radiation shielding GCs is even 34 % lower than that of normal concrete. This study highlights the advantages of geopolymer and CRT glass in developing sustainable radiation shielding materials for nuclear technology and medicine fields. • Sustainable radiation shielding materials were designed by recycling CRT glass in GCs. • Microstructure and interface property of CRT glass-enhanced GCs was detailed evaluated. • γ-ray shielding capacity of CRT glass-enhanced GCs was 9 % higher than that of normal concrete. • Carbon footprint of CRT glass-enhanced GCs was 34 % lower than that of normal concrete.