As part of sustainable development, the German cement industry is committing to conserving natural resources and exhausting potential for substitution along the value creation chain. In 2015, around 16 per cent of the raw materials used in cement manufacture were alternative raw materials – particularly in clinker production and as aggregate materials in cement grinding.
Sludge from drinking water treatment, waste foundry sand from metal processing and fly ash from coal and lignite-fired power plants used for clinker production made up 1.8 per cent of the raw material used in the burning process. This proportion is, however, dependent on a very limited supply of suitable materials. For example, a considerable reduction in the volume of fly ash is to be expected as part of the change in German energy policy, which could reduce the substitution quota in this area. The substitution quota for cement grinding is considerably higher, at 21.5 per cent in 2015. Granulated blast furnace slag is particularly significant, occurring as a by-product in production of pig iron. Around 11 million tonnes of limestone can be saved each year by using approx. 7 million tonnes of substitute.
Alongside this, the German cement industry is also focusing primarily on the use of alternative raw materials when it comes to its energy requirements. Companies have been continually increasing the proportion of alternative fuels in thermal energy input, and have been able to more than double this since 2000. The substitution rate was over 64.7 per cent in 2015, therefore on a very high level in terms of international comparison: the EU average was around 34 per cent in 2013.
Resource-conserving measures area also being implemented in the manufacture and use of concrete. Whilst cement cannot be used again after being used as a binder, concrete can be fully recycled as aggregate (e.g. as part of building demolition or tear-down). Nevertheless, it is clear that primary raw materials must play an important role in future as high quality requirements for products only permit use of recycled materials for certain types of application.
The topic of resource efficiency is playing an increasingly important role on European level. By publishing the "A resource-efficient Europe" initiative and "Roadmap to a Resource Efficient Europe" in 2011, the European Commission officially set detachment of economic growth from raw material requirements as a key theme of raw materials policy. Minimum environmental standards are to be introduced by 2020 in order to push products with low resource efficiency out of the market. Such standards do, however, bring the risk that politics will pursue targets that cannot be met within the scope of technological and economic limits.
Resource efficiency is also being given great importance on Germany's national political level. In order to make progress in productivity in the field of abiotic and non-energy raw materials, the German resource efficiency programme (ProgRess) was passed on 29 February 2012 and updated as ProgRess II in 2016. In essence, the document contains ten specific economic and recycling targets, as well as relevant indicators to measure the respective degree of target achievement. With regard to the construction industry, ProgRess II requires an increased use of recycled aggregates as concrete additive until 2030.
The political targets of the EU Commission and the German government on increasing resource productivity require methods for measuring progress already achieved. The EU Commission's suggestion from 2012 foresees a guide indicator that shows resource productivity as a ratio between gross domestic product and domestic material consumption per tonne in euros. However, this indicator completely ignores key raw material and product-related differences, and is unable to adequately convey the actual efficiency of raw material use. For this reason, a differentiated approach is required in the development of suitable indicators, allowing for the relevant raw material and product-related conditions and value of the raw material over the entire life cycle to be highlighted.