© 2021 JETIR November 2021, Volume 8, Issue 11 www.jetir.org (ISSN-2349-5162) JETIR2111193 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org b751 Thermal and gamma radiation shielding properties of geopolymer high density concrete 1 Gowtham S Raj, 2 Divakar L 1 PG student, 2 Assistant Professor 1 Department of Civil Engineering, 1 M.S Ramaiah University of Applied Sciences, Bengaluru, India Abstract: This paper provides a review about the thermal and radiation shielding properties of geopolymer concrete. Geopolymer concrete is a type of concrete that is made by reacting aluminate and silicate bearing materials with a caustic activator. commonly, waste materials such as fly ash or slag from iron and metal production are used which helps to lead a cleaner environment. Radiation- shielding concrete (RSC) is used in nuclear power plants, health care facilities in conducting radiation therapy, nuclear research facilities, and storage/transport casks for radioactive waste. In RSC mixtures, high-density aggregates are used to attenuate gamma rays and light atomic weight aggregates are used to absorb neutrons, so their properties and proportions will affect a mixture’s radiation-shielding characteristics. Heavyweight concrete is extensively used as a shield in nuclear plants, radio therapy rooms and for transporting as well as storing radioactive wastes. For this purpose, concrete must have high strength and density. Heavyweight and high strength concrete can be used for shielding purposes. Such concrete with magnetite aggregates can have a density in the range of 3.2–4 t/m3, which is significantly higher than that with normal aggregates. Index Terms - Geopolymer concrete, Compressive strength, Attenuation coefficient, Silica fumes & Fly ash. I. INTRODUCTION Concrete is by far the most widely used material for reactor shielding due to its cheapness and satisfactory mechanical properties. It is usually a mixture of hydrogen and other light nuclei and has a high atomic number. The aggregate of concrete containing many heavy elements plays an important role in improving concrete shielding properties and therefore has good shielding properties for the attenuation of photons and neutrons (Santhoshkumar, et al., 2013). The density of heavyweight concrete is based on the specific gravity of the aggregate and the properties of the other components of concrete The development of nuclear technology is one of the most significant achievements of the twentieth century. Nuclear technology is currently being used nearly in every field and aspect of human activity - from medicine, manufacturing, agriculture to producing electricity for over 16% of world-wide needs (Wang, et al., 2007). Particle accelerators such as medical cyclotrons accelerate particles to bombard a target to produce radio-nuclides such as fluorine-18. Such bombardment also produces neutrons and gamma rays which are to be shielded. Cyclotron of low-energy (11-12 MeV proton energy) systems come equipped with their own built-in radiation shielding. Others, however, are higher-energy (16-18 MeV proton-energy) accelerators which are intended for installation in a specialized concrete vault for (Alhajali, et al., 2012) radiation protection. Radiation-shielding concrete (RSC) is used in nuclear power plants, health care facilities in conducting radiation therapy, nuclear research facilities, and storage/transport casks for radioactive waste. In RSC mixtures, high-density aggregates are used to attenuate gamma rays and light atomic weight aggregates are used to absorb neutrons, so their properties and proportions will affect a mixture’s radiation-shielding characteristics. The most common naturally occurring aggregates used in RSC are produced from ores of high- density minerals such as hematite, ilmenite, magnetite, and barite (Lee, et al., 2013). Other aggregates used in RSC include aggregates that contain bound water, produced from ores of hydrous iron, serpentine, or bauxite, and aggregates that contain boron, produced from natural borate ores. The high-density aggregates used in RSC are produced from ore deposits, which contain metallic opaque phases providing the shielding properties to the RSC. Some of the natural minerals used as aggregates in high density concrete are hematite, magnetite, limonite, barite and some of the artificial aggregates include materials like steel punching and iron shot. Bauxite, hydrous iron ore or serpentine, all slightly heavier than normal weight concrete can be used in case of a high fixed water content (Ravindrarajah, et al., 2002). Heavyweight concrete is extensively used as a shield in nuclear plants, radio therapy rooms and for transporting as well as storing radioactive wastes. For this purpose, concrete must have high strength and density. Heavyweight and high strength concrete