Verification of Mechanical Properties of Recycled Concrete in Regulatory Relations

Around 25 billion tons of concrete is used each year globally that means over 3.8 tons per person in the world each year. Occupying about 60% to 70% of the volume, aggregate is a main ingredient of concrete. Nowadays, there is an increasing trend toward using sustainable concrete and reusing of aggregates from demolished concrete is one way to achieve this aim. Although using recycled concrete aggregate (RCA) does not lead to significant reduction of CO2 emission, but it reduces using natural resources (natural aggregate) as well as helping to reduce dumping construction and demolition wastes in landfills. More than 900 million tons of construction and demolition waste is produced each year only in Europe, the U.S., and Japan. A comprehensive literature review on mechanical properties of recycled aggregate concrete (RAC) including compressive strength, splitting tensile strength, modulus of elasticity and modulus of rupture is presented. In addition, databases are created for mechanical properties of RAC in order to lead to changes or acceptance in design codes and standards’ provisions. These data were compared with the American, European, Australian, Japanese, Canadian standards provisions. Results of this study show that existing code provisions are not always conservative for mechanical properties of RAC.