I know our focus in Doors 8 is supposed to be on social infrastructures, but interesting material on the hard kind keeps turning up, too. I found a report about rocks and rubble, for example, which describes a more sustainable system of resource management. The life cycle of construction minerals is complex and involves many players: quarries, industrial processors, manufacturers, transporters, construction companies and waste disposal operators. The 4sight project has used mass balance and other modelling tools to identify and assess the impacts associated with the various processes and operations in the life cycle of construction minerals. If you like the hard stuff read more here.