Journal of Building Engineering 58 (2022) 104960 Available online 19 July 2022 2352-7102/© 2022 Elsevier Ltd. All rights reserved. Effect of aggregate and fbre types on ultra-high-performance concrete designed for radiation shielding Abdullah M. Zeyad a , Ibrahim Y. Hakeem b , Mohamed Amin c , Bassam A. Tayeh d, * , Ibrahim Saad Agwa c, e a Civil Engineering Department, College of Engineering, Jazan University, Jazan, Saudi Arabia b Department of Civil Engineering, Najran University, Najran, Saudi Arabia c Civil and Architectural Constructions Department, Faculty of Technology and Education, Suez University, Egypt d Civil Engineering Department, Faculty of Engineering, Islamic University of Gaza, P.O. Box 108, Gaza Strip, Palestine e Department of Civil Engineering, El-Arish High Institute for Engineering and Technology, El-Arish, North Sinai, Egypt A R T I C L E INFO Keywords: Ultra-high-Performance concrete Heavyweight Radiation shielding Fibre types Elevated temperature Mechanical properties Density ABSTRACT This research examines the properties of ultra-high-performance (UHPC) and heavyweight radi- ation shielding concrete (UHPHSC). Several types of heavy-weight fne aggregates (sand, magnetite, hematite ilmenite and barite) were used to achieve these properties. In addition, the different types of fbres (steel fbre, lead fbre and basalt fbre) with a volume fraction of 2% were used. The fresh properties of workability and density, and hardened properties of compressive strength, splitting tensile strength, fexural strength, and water permeability were studied. Ra- diation attenuation was measured at two different gamma-ray energies at 137 Cs0.662 and 60 Co 1.173 (MeV) sources. Linear attenuation coeffcient, half-value layer and tenth-value layer were evaluated. UHPHSCs were exposed to different temperatures at 22 ◦ C, 250 ◦ C, 500 ◦ C and 750 ◦ C to study their effect on the compressive strength and the mechanical shielding properties of gamma rays. The highest density of concrete, 3850 kg/m 3 , was achieved using magnetite aggregate and steel fbre. Although the highest compressive strength of 180.6 MPa was achieved using Ilmenite aggregate and steel fbre, the best radiation protection properties were achieved using lead fbre and magnetite aggregates. 1. Introduction The world is witnessing a growing interest in radioactive sources as an alternative for energy production and for applications in the medical and military felds [1,2]. Therefore, the diversity of radiation sources and the process of transferring them from laboratories and factories require protection to avoid health and environmental risks [3,4]. Ionizing radiation, such as gamma rays, is emitted by radionuclides. It spreads into the surrounding environment and cannot be easily controlled, thereby penetrating walls and human bodies. Therefore, providing high-effciency protection shields to prevent transmission and spread is imperative for constructing radiological construction [5]. In concrete technology, researchers have found the possibility of using some types of concrete to mitigate or completely prevent radiation transmission through construction elements [6]. Therefore, concrete has received signifcant attention due to its signifcance to adapt to structures, ease of availability of materials, low cost, reliable protection against gamma rays and high durgamma-rays. Other advantages are high strength, controllable properties, non-hazardous materials and convenient moulding on * Corresponding author. Civil Engineering Department, Islamic University of Gaza, Gaza, Palestine. E-mail address: btayeh@iugaza.edu.ps (B.A. Tayeh). Contents lists available at ScienceDirect Journal of Building Engineering journal homepage: www.elsevier.com/locate/jobe https://doi.org/10.1016/j.jobe.2022.104960 Received 20 May 2022; Received in revised form 29 June 2022; Accepted 11 July 2022