PERFORMANCE AND DURABILITY OF SUSTAINABLE CONCRETE MADE WITH AGGREGATES PRODUCED FROM RETURNED CONCRETE

Giorgio Ferrari, Mitsuya Miyamoto, Alberto Ferrari, Kenichi Yoda, Michele Secco

Abstract: Concrete is the second most used material in the world, after water. More than 10,000 million cubic meters are globally produced every year, with the consumption of more than 19,000 million tons of natural aggregates (coarse aggregates and sand). About 200 million cubic meters of concrete (2 per cent of the global production) are not placed at the jobsite and are returned to readymixed plant where, in most cases, are disposed as waste material. Recently, a new technology to treat returned concrete has been developed. By the new technology, one cubic meter of returned concrete is transformed into 2.3 tons of aggregates, without any waste production. New concrete materials, made by 100 % aggregates produced with the new technology, have been developed in Japan and used in many construction sites. In the present paper, the aggregate production process from returned concrete is reviewed, the composition and design of the new concrete materials are discussed and the mechanical performance and durability tests of the new concrete are presented. These new concrete materials represents an important contribution to concrete sustainability, in terms of natural resources protection, waste disposal and economical benefit both for the ready-mixed plant and the general contractor

Keywords: Aggregates, durability, natural resources protection, recycling, returned concrete, sustainability

DOI: https://doi.org/10.15623/ijret.2014.0325029