Properties of various size fractions of crushed concrete related to process conditions and re-use

Recycled concrete aggregates are mainly used for road construction, but another interesting application would be their incorporation into concrete mixes. So far, such an application is hindered by the loss of mechanical properties of recycled aggregate concrete. However, through an efficient crushing technique, which is able to generate relatively clean aggregates, recycled concrete can be a beneficial addition. This study deals with properties (particle size distribution, density, thermal treatment reaction, oxide and mineralogical composition) of a large number of recycled concrete fractions, obtained through three crushing methods. The use of recycled concrete sand, i.e. particle sizes between 150 μm and 2 mm, in new concrete is proven to be promising when the right crushing technique is adopted.