Background

The CSI established a new 'Concrete Recycling' Task Force in 2005 to consider the sustainability issues related to concrete as a sustainability material. Many industries try to consider “cradle-to-grave” responsibility for their products, but cement is an intermediate product, which must be combined with other materials to be turned into concrete. Cement companies have little control over how concrete is used.

What does recycling mean? Our initial online stakeholder dialogues revealed some confusion in peoples’ minds about the nature of concrete recycling. Some materials, like aluminum cans and glass bottles, can be reclaimed and recycled into more of the original product: new cans and bottles. The energy and material savings are substantial, and there are high consumer recycling rates in many countries. Concrete, however, while made from cement, cannot be recycled into more cement. Once concrete has been made, there is no practical way to decompose it into the basic elements of sand, water, aggregate and cement that went into its formation. However, there are opportunities to crush and reuse concrete recovered from construction demolition. The recycled material can be substituted for fresh aggregate in some applications.

The task force has established a ‘Best Practice’ group to better understand current practices, incentives and barriers to greater recycling of concrete. A report detailing the task force’s progress will be published by the end of 2008. This online dialogue aims to incorporate stakeholder's views into this report.