Sulfatna otpornost betona na bazi recikliranog agregata

Abstract

U disertaciji su prikazani rezultati sopstvenog eksperimentalnog istraživanja sulfatne otpornosti betona sa recikliranim agregatom. Istraživanje je zasnovano na komparativnoj analizi dve grupe betona koje se razlikuju u krupnom agregatu, a u okviru kojih su varirani dve vrste cementa i dva vodocementna faktora. Sulfatna otpornost je proveravana nakon 3 i 6 meseci boravka u 5% Na2SO4 i u 5% MgSO4. Na očvrslom betonu ispitivani su kapilarno upijanje vode, promena dužine uzoraka, čvrstoća pri pritisku i urađene su mikrostrukturne analize: MIP, SEM, BSE/EDS, XRD i FTIR. Istaknuto je da se primenom krupnog agregata od recikliranog betona i veziva odgovarajućeg mineraloškog sastava mogu dobiti konstrukcijski betoni, odnosno betoni sa zadovoljavajućim mehaničkim karakteristikama, ali i sa zadovoljavajućom trajnošću sa aspekta sulfatne korozije.

This paper presents the experimental research results of the sulphate resistance of concrete with recycled aggregate. The research is based on a comparative analysis of two groups of concrete that differ in coarse aggregate types. Within these two concrete groups, two types of cement of the same class and two water/cement ratios have been varied. Sulphate resistance was examined after 3 and 6 months of immersion in 5% Na2SO4 and 5% MgSO4. Capillary water absorption, sample length change and compressive strength were studied in hardened concrete and the following microstructural analyzes were performed: MIP, SEM, BSE/EDS, XRD and FTIR. It has been found that structural concrete with apppropriate mechanical properties as well as with satisfactory durability from the aspect of sulphate corrosion can be obtained by combination of a coarse recycled concrete aggregate and a binder of an appropriate mineralogical composition.