Use of Construction and Demolition Waste in Concrete Production

This article presents the results of a research dealing with the use of construction and demolition waste - recycled concrete in the production of fresh concrete, as a partial substitute for natural aggregate. It describes the properties of concrete recyclate that is used for the proposed recipe of fresh concrete. The properties include the results of grain size analysis, bulk density and water absorption capacity. 2 recipes of fresh concrete were prepared for the research. Recipe 1 based on recycled concrete combined with natural aggregate fraction (fr.) 8/16 mm. Recipe 2 based on natural aggregate, which also served as the comparison recipe to demonstrate the effect of recycled concrete fr. 0/16 mm on the physical-mechanical and deformation properties of concrete. The presented results show that the substitution of natural aggregate fr. 0/16 mm with recycled concrete has caused: a reduction of cubic strength by about 12%, crushing strength of cylinders by about 7%, and static and dynamic modulus of elasticity values by about 22% and 25%.