Contents lists available at ScienceDirect Engineering Structures journal homepage: www.elsevier.com/locate/engstruct Review article Potential use of rubber as aggregate in structural reinforced concrete element – A review Kristina Strukar a , Tanja Kalman Šipoš a, ⁎ , Ivana Miličević b , Robert Bušić b a Department for Technical Mechanics, Faculty of Civil Engineering Osijek, Vladimira Preloga 3, Osijek, Croatia b Department for Materials and Structures, Faculty of Civil Engineering Osijek, Vladimira Preloga 3, Osijek, Croatia ARTICLE INFO Keywords: Rubber Aggregate Concrete Structural elements ABSTRACT Utilization and reuse of waste rubber tires in concrete leads to sustainable construction. There are number of studies that have been conducted on concrete with rubber as aggregate in order to maintain mechanical properties and durability of material. Contrary, only several studies have been conducted on usage of waste rubber tires as aggregate in reinforced concrete elements and systems. These review paper summaries and compare independent research works and justifes weather these aggregates are possible to utilize improved behavior of concrete elements or not. According to general conclusions on fundamental properties of rubberized elements it is evident that the waste rubber tire aggregates can be used as partial replacement of both coarse aggregates and fne aggregates. Previous research on structural elements shows that replacement of the natural aggregate with recycled tire aggregate in concrete, will produce structural elements with improved behavior: increased capacity for de- formations (ductility), better dissipation of energy, and higher damping, in comparison with standard concrete made with conventional aggregates. However, the increased content of rubber in concrete also has negative efects, for example reduction of compressive and tensile as well as reduction of Young's modulus of elasticity. The results of these experimental studies are not sufcient to reach a general consensus on the application of recycled rubber in concrete and its efect on the behavior of structural elements. Inconsistency of the efects of recycled rubber in the concrete on the static and dynamic properties of reinforced-concrete structures indicate that there is uttered need for further research. 1. Introduction Unrecycled tire waste is an enormous global problem because of their non-biodegradability, their fammability and their chemical composition which lead to another problems such as landflling, health, and environmental challenges. According to report of European Tyre & Rubber manufacturers’ association (ETRMA) [1]. 1.4 billion tires are annually made to meet the needs of the global industry, and the annual amount of tire waste created in the European Union member states alone is 3.5 million tones. According to the Directive 1999/31/EC [2], starting from 2006, disposal of waste tires in the environment is com- pletely forbidden, and when taking that fact into account, the amount of tire waste has increased signifcantly. The inability of landflls to properly deal with the disposal of tires has spurred the research into ways to successfully recycle tires into commodities and resources, such as concrete, asphalt, playground surfaces, sports feld, various coverings and other tires [3]. Currently only 5% of recycled waste tires are used in construction [4], even though the potential is much greater. One of the research directions in recent years is the use of waste tires in technologies for the production of concrete which is the most used material in construction and consumes large amount of natural resources. Thus, waste tire rubber fnds its use in concrete as a sub- stitute to natural aggregate or as a substitute to cement. However, it must be frst reduced in size and then recycled. Mechanical recycling process includes ripping of tires to larger pieces or shreds, and from those using technology of multiple mechanical fragmentation of waste tires, tire rubber granulates or tire rubber powder is produced. Diference in shredded, granulated or powder tire rubber is in their size which can be 20–30 mm, 1–10 mm, and less than 1 mm, respectively [5]. From the literature review presented in this study one can conclude that the advantages of the use of recycled rubber in concrete, when compared to standard concrete, are: increased hardness, increased https://doi.org/10.1016/j.engstruct.2019.03.031 Received 24 August 2018; Received in revised form 1 February 2019; Accepted 11 March 2019 ⁎ Corresponding author. E-mail addresses: kstrukar@gfos.hr (K. Strukar), tkalman@gfos.hr (T. Kalman Šipoš), ivana.milicevic@gfos.hr (I. Miličević), rbusic@gfos.hr (R. Bušić). Engineering Structures 188 (2019) 452–468 0141-0296/ © 2019 Elsevier Ltd. All rights reserved. T