Innovative use of local by-products for environmentally friendly construction products

The main goal of this project is to use locally available industrial by-products like fly ash and slag in order to replace partially portland cement and therefore reduce the carbon footprint of industrial mortars.

Ordinary Portland cement (OPC) is the main used binder in industrial mortars like plaster, render, tile adhesives and floor screeds. OPC has been used for many decades with big success, and most of the properties of the industrial mortars during application as well as their long term durability are well known and worldwide accepted. On the other hand, the manufacturing process of OPC is one of the biggest contributors to worldwide CO2 emissions (5%). This is due to two main reasons: the calcination of CaCO3 (limestone) directly emits carbon dioxide by the chemical reaction during the burning process. The necessary process temperature is about 1450°C; to develop this heat in the rotary kiln marks the second source of CO2 emission. Altogether it stands for 0.8 - 1 ton CO2 release for the production of 1 ton OPC. The hardening process of OPC in concrete and industrial mortars runs via the hydraulic reactivity: a chemical reaction called hydration of the main clinker phases: tricalcium silicate (C3S, alite), dicalcium silicate (C2S, belite) and tricalcium aluminate (C3A, aluminate). Looking at the chemical composition, many industrial by-products (waste) from production of power, heat or chemicals have many similarities with OPC. These (alumino silicate) materials have certain reactivity when mixed with water. The reactivity is lower compared to OPC, therefore these materials are called latent hydraulic or pozzolanic raw materials. An important representative of such interesting by-products is fly ash. This is a reaction product of the combustion of coal - anthracite or lignite coal in thermal power plants. Since it is forbidden in the meantime in most of the European countries to emit fly ashes via large chimneys they are precipitated via filters, mainly electrofilters. Most of the fly ashes in the Southeast European countries are landfilled today. By that, thousands of tons of valuable raw materials today end up in a deposit and consume valuable land. The CO2 footprint of fly ash is very low: approximately 20 kg CO2 per 1 ton of fly ash (compared with 1.000 kg CO2 for one ton of OPC). According to our idea this is not necessary since most of these fly ashes bear a certain pozzolanic reactivity which makes them a top candidate for either a partial or complete replacement of Portland cement. The topic of our project is to characterize local industrial by-products, focusing on fly ashes compared to OPC. Our aim is to develop new technologies which will allow us to use less OPC in industrial mortars and use fly ash instead. By that we can solve several problems at once: - We will help to reduce the consumption of OPC and by that we reduce the CO2 emission of the construction materials dramatically - That will help the countries engaged to reduce the CO2 emission (Kyoto protocoll) - We will help to upcycle local industrial by-products like fly ash - That will help the countries involved to reduce quantities of the materials that had to be landfilled, which is costly and bears negative impacts on environment. We can rely on a strong background of the project team from Institute for Multidisciplinary Research Belgrade University, Serbia, in valorization of local by-products, such as fly ash, in building materials industry (tiles, Portland cement clinker, new type of binders – geopolymers etc.). On the other hand, Weber Saint-Gobain has long time experience using Supplementary Cementitious Materials like slag as binder or co-binder in their industrial mortars and good progress made in green binder development in 2012. Current development leads to a new mineral binder with no or less OPC based on slag as low carbon footprint raw material to reduce CO2 emission by at least 50%, two patents have been filed so far. Based on this know how Weber Romania and Weber Serbia intend to develop similar technologies that use local by-products.
Project ID: 
9 980
Start date: 
Project Duration: 
Project costs: 
800 000.00€
Technological Area: 
Building Materials, Components and Methods
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.