the conscious waste handling is getting more important worldwide. in the past fifteen years several detailed decrees and regulations were issued, dealing with this topic. the independent category of industrial waste of the construction industry is about 15-years old as well. in our research, the opportunities in recycling autoclaved aerated concrete (AAc) waste were investigated. AAc is a rather young building material, compared to the ancient ones, e.g. concrete, wood, or natural stone. the first factory, producing this material, was founded in 1929, in sweden, and the first one in Hungary in 1963 (at kazincbarcika). the following question has been raised: What is going to happen with the large amount of AAc building elements (mainly in family houses) when they reach their design lifetime, and are to be demolished, creating AAc waste? in our research, different ways for recycling this material were investigated. our theories were confirmed by laboratory tests. our ultimate task was to develop some new, useful concrete products, made from AAc waste. in the past 3 years, two research phases were finalized, both for different purposes of use. in the first phase, load bearing and insulating lightweight concrete mixtures with crushed AAc aggregate have been made. in the second phase, the mixtures were designed for vertical covering applications. Laboratory tests were made according to european and Hungarian standards. keywords: Autoclaved aerated concrete (AAc), cellular concrete, building industrial waste, recycling, lightweight aggregate concrete (LWAc) olivér Fenyvesi, Phd civil engineer (msc), monument protection engineer, PhD, Assistant Professor at Bme Dept. of construction materials and technologies. main fields of interest: early age shrinkage cracking of normal and lightweight concretes, application of recycled waste materials for concrete (normal and lightweight aggregates), protection of building heritage, construction diagnostics, corrosion of reinforced concrete and steel structures. secretary of the szte concrete Division, member of fib Hungarian Group. bence JanKus 5 th-year architecture student in the Budapest university of technology and economics, Faculty of Architecture. main fields of interest: Lightweight aggregate concretes, recycling building industrial waste as concrete aggregate, especially AAc.
