Sustainability benefits of lightweight concrete Recycling of lightweight concrete

摘要

The ongoing discussion on closed-loop recycling is increasingly focusing on the construction industry which uses significant amounts of mineral resources and counts among the large waste producers. In excess of 50 mio. tons of demolition waste are generated each year, frequently including a mixture of different components. New concepts and technologies are needed for their recovery. The increasing diversity of materials poses a problem. Homogeneous material fractions free from foreign and undesirable substances are required, for example, for concrete construction. By 2020, the manufacturers of construction products must submit concepts on how to recirculate recycled mineral aggregates for use in the production process. Demolished lightweight concrete waste is generated in two different qualities: unmixed production waste or mixed materials after demolition or deconstruction. The required percentage of unmixed fractions can be added to the lightweight concrete production process, which is currently done for products intended for use in garden and landscape architecture. Contrary to ordinary concrete recycling, this results in an increased bulk density and improved mechanical properties.