Using construction and demolition debris as a substitute for natural aggregate in producing concrete mixtures is gaining more and more supporters because of both economic and ecological reasons. The use of construction and demolition debris means limiting the use of expensive natural aggregate, and thus minimising the negative impact on the natural environment. The maximum benefitis achieved when the biggest possible amount of re-cycled aggregate is used in the production of concrete. It is to be hoped that the continuous development of technologies in the construction sector will lead to minimising the amount of waste as well as to increasing the number of materials undergoing the recycling process and reused to building new structures.