We work on concrete from recycled aggregate

News, 14/11/2019

Czech companies and scientific institutions are involved in the development of concrete from construction debris, which is cheaper and, in addition, boasts a lower carbon footprint than conventional material. Among them is the University Center for Energy Efficient Buildings of CTU, whose specialists also participated in the public debate on the advantages and pitfalls of recycled materials.

The construction industry is likely to increasingly face problems with the landfilling of demolition debris and dwindling aggregate and sand supplies. In addition, the pressure to save cement will increase, the production of which is responsible for roughly 8% of global CO2 emissions. Under Terezy Pavlů and Antonína Lupíška from CTU UCEEB, the solution to these questions could be the wider use of recycled materials in concrete.

With their research team, they are therefore testing new possibilities of using recycled materials in the laboratories of Bustěhrad, which could eventually become a full-fledged substitute for natural materials in concrete if the standard requirements are adjusted. "We replace the sand with a fine fraction of recycled aggregate. The standard does not yet allow this, because the normal fine fraction contains a high proportion of clay components. However, we are with the company AZS98 within the first year of the project, they designed an improved recycling technology so that the clay components were removed from the recyclate. Thanks to this, it will be possible to use our fraction without a negative effect on the properties of concrete," says Tereza Pavlů.

Saving cement is an even more fundamental challenge for researchers. A number of research teams around the world are working on this topic, taking different approaches. We are looking for a new binder that will fulfill the function of cement and at the same time have a lower carbon footprint, new fillers, and experimenting with alternative ways of reinforcing concrete. At the same time, we are looking for ways to generally save the materials we use in the construction of buildings, in accordance with the principles of the circular economy.

CTU UCEEB in cooperation with Českou agenturou pro standardizaci created an overview of construction materials that can be recycled in the construction industry: http://www.recyklujmestavby.cz/

You can play the entire Czech Radio interview with Tereza Pavlů, Antonín Lupíšek and other experts here: https://plus.rozhlas.cz/mame-svaty-gral-cesky-zeleny-beton-je-revoluci-ve-stavebnictvi-8096062