The production and properties of cold-bonded aggregate and its applications in concrete: A review

The rapid increase in waste quantities, as well as the depletion of the natural resources in the near future are some of the major concern worldwide. In response to these problems, as well as to the growing demand for concrete in the construction field, the focus has been directed towards the production of artificial aggregates, as an alternative to natural ones. Artificial aggregates are produced either by sintering or cold bonding method. Compared with the sintering method and besides being an effective recycling solution for a wide variety of wastes and by-product materials, the cold bonding method is characterized by minimal energy consumption, low pollutant emissions and low investment requirements. The use of cold bonded aggregate as a potential construction material in concrete production is summarized in this manuscript. The paper discusses factors influencing manufacturing productivity and the properties of cold bonded aggregate, such as pelletizer disc angle and speed, pelletization duration, water content and the types of raw materials and binders used. The physical properties of cold-bonded aggregates made of different waste materials and binders are presented. The mechanical characteristics, thermal properties and durability of concrete made of cold-bonded aggregates are also reviewed. The literature in the field has established the potential of using cold-bonded aggregates as sustainable materials in the production of normal-weight concrete, as well as structural and nonstructural lightweight aggregate concrete. (C) 2019 Elsevier Ltd. All rights reserved.