The cumulative energy expenditure and the resulting CO2 emissions were determined for the production of drainpipes from concrete and steel reinforced concrete. By way of example, pipes with a nominal width of DN 500 were examined. In order to compare these pipes with other materials in terms of the ecological balance, the specific energy requirement and the specific CO2 emissions were defined per metre of pipe. In relation to the other materials illustrated here (stoneware, plastic and cast iron), it proves to be the case that the lowest energy requirement and the lowest CO2 emissions occur in the manufacture of pipes from concrete and steel reinforced concrete. In order to eva- luate the sustainability of the various materials, the developments since 1990 in the generation of electricity, the manufacturing of cement and the production of steel were analysed, since these three areas dominate the cumulative energy expenditure and the associated CO2 emissions. The potentials for saving energy in the production of the different materials are discussed.
Institut für Strömungstechnik und Thermodynamik
39106 Magdeburg, Germany