Large Concrete Rubble as a New Structural Construction Material: Opportunities and Digital Processes for Load-Bearing Walls

Concrete is amongst the most wasted materials on earth, mainly due to building demolitions. Currently, after a building’s end of life, concrete is crushed to be used as replacement gravel in new concrete mixes or for backfilling. Aiming to increase the circularity of the construction industry, this article presents design explorations and a design-to-construction process for building single-leaf masonry walls from large flat demolition concrete rubble, thus avoiding the need for further crushing after initial demolition. The proposed process augments the capabilities of conventional construction machinery with new digital control and sensing devices that are widely available on the market and at low cost. The design-to-construction process is implemented through methods of physical prototyping and load testing of a full-scale demonstrator to benchmark the construction precision and the structural, environmental, and productivity performances. The results highlight the viability and scalability of the approach, calling for a more systematic reuse of concrete rubble as it allows for the construction of low-carbon masonry structures while diverging part of concrete waste from downcycling and landfilling.