The building explosion during the years 1945-1960 will inevitably lead
to increased demolition in the next decades since the lifetime
distribution of structures no longer fulfills its functional social
requirements in an acceptable way. In the building period mentioned
there was a great increase in reinforced and prestressed concrete
construction. Consequently there is now more and more concrete to be
demolished. Increasingly severe demands will be made upon demolition
technology, including the demand for human- and environment-friendly
techniques. On the other hand, the possibility of disposing of debris by
dumping is steadily diminishing, especially close to major cities and
generally in countries with a high population density. At the same time
in such countries and in such urban areas a shortage of aggregates for
making concrete will develop as a result of restrictions on aggregate
working because of its effect on the environment and because of the
unavailability of aggregate deposits due to urban development. From the
foregoing it follows that recycling and re-use of environment- and
human-friendly demolished and fragmented building rubble should be
considered. The translation of this general problem into terms of
materials science is possible by forming clear ideas of adhesion and
cohesion: the whole process of demolition, fragmentation, and recycling
or re-use of concrete is to break the bonding forces between atoms and
molecules and to form new bonds across the interfaces of various
particles of either the same nature or a different nature.