BRE IP6/04 PDF

Long-term durability studies have been undertaken on concrete made from a number of crushed rock sources at present little used in concrete. The information is needed for assessing the resource potential of these materials and to give specifiers and their clients confidence of lifetime performance in structures. After 20 years of unsheltered outdoor exposure, concretes made with porous sandstone aggregates from NW England have mostly performed well in resisting frost damage and protecting embedded metal. Aggregates producing poorer performance were found to have high shrinkage and were clearly uneconomic to use because of the poor strength development of concrete made with them. However, it is concluded that a significant proportion of sandstones from NW England constitute a valuable resource and no special testing is needed beyond standard concrete cube tests and drying shrinkage.