Experimental investigation of recycled aggregate concrete

Abstract

As a result of increasing global environmental awareness and sense of responsibility for future generations utilization of demolition waste as a source of aggregate for structural concrete have been proposed. Financial gains from reducing transport fees of natural aggregate and avoiding paying high disposal costs for demolition rubble, has also been recognized. The aim of this paper is to introduce recycling process and objectives of sustainable development in civil engineering, to the domestic scientific public, by survey and analysis of own experimental investigation of recycled aggregate and concrete made of it. Physical and mechanical properties of recycled concrete aggregate were determined as crucial part for concrete mixtures design. The replacement levels of recycled coarse aggregates were 50% and 100% in separate mixtures. Concretes with both fine and coarse natural aggregates and with the same effective water to cement ratio as those concretes, were designed and tested also. Tests were conducted to determine the physical and mechanical properties of fresh (slump and density) and hardened (density, compressive and tensile splitting strength) concretes.

Korišćenje građevinskog otpada kao izvora agregata za proizvodnju novog betona rezultat je podizanja nivoa ekološke svesti i odgovornosti za život budućih generacija, kao i prepoznavanje ekonomskog interesa iskazanog kroz smanjenje troškova transporta prirodnog agregata i izbegavanje plaćanja taksi za zakup deponija. Cilj ovog rada je da kroz pregled i analizu rezultata sopstvenih eksperimentalnih istraživanja recikliranog agregata i betona spravljenih sa njim, zainteresuje domaća inženjerska javnost za primenu betona na bazi recikliranog agregata u elementima armiranobetonskih konstrukcija i održivo građevinarstvo uopšte. Kao neophodni deo pripreme za projektovanje sastava betona ispitana su fizičko-mehanička svojstva recikliranog agregata. Variran je procentualni sadržaj krupnozrnog recikliranog agregata u betonima, u iznosima od 50% i 100%, uz izradu uporednih betona sa prirodnim agregatom i sa istim efektivnim vodocementnim faktorima. Ukupno je spravljeno 9 betona, a rezultati se odnose na ispitivanje čvrstoća pri pritisku i pri zatezanju cepanjem, kao i osnovnih svojstava svežeg betona - konzistencije i zapreminske mase.