Primerjava lastnosti betonskih mešanic iz naravnega in recikliranega agregata : diplomska naloga

Trebušak, Robert (author), Bokan-Bosiljkov, Violeta (mentor)

Reciklirani agregat, pridobljen iz betonskih ruševin, predstavlja potencialno zelo kvalitetno sekundarno surovino za uporabo v betonskih mešanicah. V okviru diplomske naloge sem primerjal lastnosti referenčne betonske mešanice z naravnim agregatom in mešanic z različnimi deleži drobljenega betona v vlogi recikliranega grobega agregata. Najprej sem v sklopu projekta COST TU1404 preizkušal osnovne lastnosti referenčne mešanice betona z naravnim agregatom iz Francije. Zrna grobih frakcij francoskega agregata so bolj porozna, kot smo vajeni v Sloveniji. Za naravni agregat sem imel podane vse potrebne lastnosti, gostoto zrn in koeficient vpijanja vode. Recikliran agregat sem pridobil z drobljenjem in sejanjem betonskih ruševin. Za ta agregat sem sam določil gostoto zrn in koeficient vpijanja vode. Ugotovil sem, da sta navedeni lastnosti recikliranega betona zelo blizu lastnostim naravnega grobega agregata iz Francije. Na podlagi sestave referenčne mešanice sem določil recepture mešanic z recikliranim grobim agregatom. Z recikliranim agregatom sem zamenjal 30%, 50% in 100% prostornine grobe frakcije v referenčnem betonu. Nato sem na mešanicah z recikliranim agregatom opravil enake preiskave v svežem in strjenem stanju betona, kot na referenčni mešanici. Pri vseh mešanicah sem posebno pozornost posvetil predpripravi agregata, da sem dosegel z vodo zasičeno površinsko suho stanje agregatnih zrn. Rezultati opravljenih preiskav so pokazali, da so imele mešanice z recikliranim agregatom v svežem stanju enako konsistenco in prostorninsko maso in nekoliko višjo vsebnost zraka, kot referenčni beton. Tudi v strjenem stanju so dosegale zelo podobno tlačno trdnost, kot referenčni beton.

• Language: Slovenian
• Keywords: gradbeništvo, diplomska naloga, VSŠ, betonske mešanice, recikliran agregat, drobljen beton
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [R. Trebušak]
• Year: 2016
• Number of pages: XVI, 44 str.
• PID: 20.500.12556/RUL-85686
• UDC: 691.3(043.2)
• COBISS.SI-ID: 7761761
• Publication date in RUL: 19.11.2016

TREBUŠAK, Robert, 2016, Primerjava lastnosti betonskih mešanic iz naravnega in recikliranega agregata : diplomska naloga [online]. Bachelor’s thesis. Ljubljana : R. Trebušak. [Accessed 26 June 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=85686

Secondary language

• Language: English
• Title: Comparison of properties of concrete mixtures made of natural and recycled aggregate

Abstract

Recycled aggregate produced from concrete rubble has potential to be high-quality secondary raw material for use in concrete mixtures. As part of the thesis, I compared properties of reference concrete mixtures (OC) with natural aggregate and mixtures with different proportions of crushed concrete as recycled coarse aggregate. OC mixture was prescribed in the framework of round robin test (RRT) of the COST TU1404 Action. I first carried out tests in the framework of the RRT, on the OC, which was prepared from natural aggregate from France. Coarse aggregate particles of the French natural aggregate have higher porosity than Slovenian natural aggregates. For the French aggregate, all the necessary properties were given by the RRT coordinator, including grain density of particular fraction and its coefficient of water absorption. Recycled aggregate was obtained by crushing and sieving of concrete rubble. The grain density and the coefficient of water absorption of coarse fractions of recycled aggregates were determined in laboratory of UL FGG. I found out that the tested properties of the recycled concrete are very close to the same properties of natural coarse aggregate from France. Based on the composition of the OC I determined the composition of mixtures with recycled coarse aggregate. I replaced 30%, 50% and 100% of the coarse fraction volume of the OC with the recycled aggregate. On the recycled aggregate concrete mixtures I carried out the same tests in fresh and hardened state as for the OC. For all concrete compositions, I paid special attention to initial preparation of aggregate that should reach water-saturated surface dry condition of the grains. Obtained test results showed that compared to the OC the recycled aggregate concrete mixtures possess the same consistency and density in fresh state and slightly higher air content. The same is true also for the hardened state, since the compressive strength results were approximately the same for the reference and recycled aggregate concrete mixtures.

• Keywords: civil engineering, recycled aggregate, crushed concrete, concrete mixtures