Structural concrete with partial or total cement replacemnet with fly ash

Abstract

Building industry is facing with great challenges in directing its activities towards sustainable development. Environmental protection, the use of waste and recycled materials and reduction of the use of non-renewable natural resources has become the focus of current research in building materials. Concrete is the most widely used man-made material in the world, and hence the pressure to reduce its harmful impact on the environment as much as possible. Production of the main component of concrete - cement, is one of the major polluters of the environment. With this in mind, research in the field of concrete materials has focused on the use of alternative binder in concrete with less harmful effects on the environment. In recent decades, concrete made with fly ash as a partial or total replacement of cement attracted a lot of attention. This paper gives an overview of the use of fly ash in concrete, as well as physical and mechanical properties of this type of concrete. High volume fly ash concrete with 50% replacement of cement and geopolymer concrete with alkali activated fly ash have been analyzed. This paper gives an overview of research done in this field in the world and own experimental results of these types of concrete made with fly ash from power plant ‘Nikola Tesla B’ from Obrenovac.

Građevinska industrija se suočava sa velikim izazovima prilikom usmeravanja svojih delatnosti na put održivog razvoja. Zaštita životne sredine, korišćenje otpadnih i recikliranih materijala i smanjenje upotrebe prirodnih neobnovljivih resursa postali su fokus aktuelnih istraživanja građevinskih materijala. Beton je danas nesumnjivo najčešće korišćeni veštački materijal u svetu, i stoga je pritisak da se njegov štetni uticaj na okolinu što više smanji. Proizvodnja glavne vezivne komponente betona - cementa, predstavlja jedan od većih zagađivača životne sredine. Imajući ovo u vidu, istraživanja u oblasti betona su fokusirana na korišćenje alterantivnih veziva u betonu koja imaju manje štetnih efekata na životnu sredinu. Poslednjih decenija veliku pažnju privlače betoni sa elektrfilterskim pepelom kao delimičnom ili potpunom zamenom cementa. U ovom radu dat je pregled mogućnosti korišćenja elektrfilterskog pepela u betonima i fizičko-mehaničke karakteristike tih betona. Analizirani su betoni sa velikim sadržajem elektrofilterskog pepela koji imaju 50% zamene cementa i geopolimer betoni u kojima je cement potpuno zamenjen alkalno aktiviranim elektrofilterskim pepelom. Dat je pregled istraživanja iz te oblasti u svetu i rezultati sopstvenih eksperimentalnih istraživanja ovih vrsta betona sa elektrofilterskim pepelom iz termoelektrane “Nikola Tesla B” iz Obrenovca.