Possibility of application of old concrete as a new kind of aggregate in modern construction

Abstract

Characteristic of the 20th century, in terms of civil engineering, is intensive construction without taking care about preservation of the natural resources and the impact of buildings on the environment in all stages of service life, especially after demolition of buildings and waste deposition. Because of that, at the end of the last century, generation of huge amounts of waste became one of the biggest environmental problems in the majority of the world. Recycling of 'old' concrete is accepted as one of sustainable solutions for the problems of construction and demolition waste (C&D) and preservation of natural resources of aggregate. The first part of the paper presents technological procedure for recycled concrete aggregate production, basic properties of obtained aggregate and properties of recycled aggregate concrete. In the second part of the paper, results of own comparative investigation of properties of common and self-compacting concrete with coarse recycled concrete aggregate, are briefly presented. It was concluded that by using of quality uncontaminated recycled concrete aggregate it is possible to produce concrete with satisfactory performances that are not different from properties of ordinary concrete produced with natural aggregate. .

Karakteristika dvadesetog veka, sa aspekta građevinarstva, je intenzivna gradnja, pri čemu se nije dovoljno vodilo računa o očuvanju prirodnih resursa i o uticajima objekata na životnu sredinu u svim fazama eksploatacionog veka, zaključno sa rušenjem objekata i deponovanjem građevinskog otpada. Zbog toga je krajem dvadesetog veka otpad postao jedan od najvećih ekoloških problema u većini zemalja sveta. Kao održivo rešenje za probleme građevinskog otpada i iscrpljivanje nalazišta prirodnog agregata, prihvaćen je postupak recikliranja, u prvom redu 'starog' betona. U prvom delu radu prikazani su tehnološki postupci za dobijanje recikliranog agregata od otpadnog betona, osnovna svojstva agregata dobijenog usitnjavanjem 'starog' betona i svojstva betona na bazi recikliranog agregata. U drugom delu rada ukratko su prikazani rezultati sopstvenih komparativnih ispitivanja svojstava običnih i samougrađujućih betona sa prirodnim i sa recikliranim krupnim agregatom. Zaključeno je da se korišćenjem kvalitetnog čistog recikliranog agregata mogu dobiti betoni koji imaju zadovoljavajuće performanse koje se bitnije ne razlikuju od performansi betona sa prirodnim agregatom. .