Clay to create sustainable concrete
Updated: Dec 1, 2020
The necessity to fulfill the sustainable requirements also in the construction industry has lead to innovative solutions for developing new materials for construction. In the building materials group at the Luleå University of Technology in Sweden, a novel sustainable material made of clay is developed.
Concrete is the second main used substance in the world, after water. Traditional concrete is made of cement, which production is contributing to approximately 8 % of the overall anthropogenic CO2 emissions. The requirement for reduction of emissions has to be fulfilled by the end of 2050 and the cement industry is facing several changes in regard. On the other hand, clay is the oldest material utilized in constructions, let´s think of the broad range of products as tiles, bricks, etc. Clay is also a commonly occurring material and several deposits are distributed worldwide. Its properties do not make it a suitable material for cement replacement in its natural form. However, different treatments can be performed.
At the Luleå University of Technology, researchers have worked with clean technologies to treat clay and make it suitable for replacing cement during concrete production. Treatment of clay is done without the utilization of high temperature or additional chemicals. Impact and friction in a ball mill can change the nature of clay and make it suitable for replacing cement contributing thus to increased sustainability of concrete.
Before construction works, it is of common use to remove soil, which has a high content of clay, because of the instability that characterizes it. This removal can generate huge quantities of clay deposits. So, why not reuse also this source? The same clean technology can improve the reactivity of the waste clay, which can be later used as a replacement of cement in concrete production, contributing thus to a circular economy and responsible consumption of resources. Clay has great potential to be broadly utilized again in construction, and innovation is the key to transform it into a novel attractive building material.
|Building Materials Group at LTU