Vpliv deleža in zrnavosti recikliranega agregata na lastnosti betona : diplomska naloga

Resman, Janja (author), Bokan-Bosiljkov, Violeta (mentor)

Skrb za okolje nas spremlja na vsakem koraku. Vpliv vedno večje ozaveščenosti in skrbi za okolje se kaže tudi v gradbeništvu, pri izbiri materialov, postopkov gradnje ter v ravnanju z gradbenimi odpadki. Pri uporabi betona se želimo čim bolj izogniti negativnim vplivom na okolje. Tudi zakonodaja s področja gradbeništva, okolja in odpadkov relativno hitro sledi odločitvam pristojnih inštitucij. Vlada RS je v ta namen v letošnjem letu sprejela Program ravnanja z odpadki in preprečevanja odpadkov RS v skladu z zakonodajo. Osnovni namen diplomske naloge je ocena vpliva deleža in zrnavosti recikliranega agregata na lastnosti betona. Poskušali smo dobiti odgovor na vprašanje, ali je mogoče zamenjati naravni agregat z recikliranim in pri tem ohraniti osnovne karakteristike svežega in strjenega betona. Pri pripravi betonskih mešanic smo uporabili dve vrsti kamenega agregata. Naravni agregat je bil dostavljen iz Francije v okviru projekta »COST Action TU1404«, recikliran agregat iz odpadnega drobljenega betona pa smo dobili na separaciji v okolici Ljubljane. Pripravo vzorcev in preiskave recikliranega agregata smo opravili v Konstrukcijsko prometnem laboratoriju, ki deluje v okviru Fakultete za gradbeništvo in geodezijo Univerze v Ljubljani. S pomočjo preiskav smo določili fizikalne lastnosti recikliranega agregata (zrnavost, delež finih delcev, modul oblike zrn, prostorninska masa, vpijanje vode, vlažnost, prisotnost humoznih delcev). Na osnovi teh smo ocenili njihovo primernost za uporabo v betonskih mešanicah. Pripravili smo tri mešanice svežega betona z enako količino cementa in enakim vodocementnim razmerjem. Prva mešanica betona je bila sestavljena iz drobne frakcije naravnega izvora in grobe frakcije iz recikliranega agregata. Druga mešanica betona je bila sestavljena iz drobne frakcije recikliranega agregata in grobe frakcije naravnega izvora. Tretja mešanica betona je vsebovala samo recikliran agregat. Lastnosti sveže betonske mešanice (konsistenca, gostota, delež vsebnosti zraka) in strjenega betona (tlačna trdnost, cepilna natezna trdnost, globina prodora vode pod pritiskom) smo preverjali v skladu z določili evropskih standardov. Na podlagi rezultatov preiskav betonskih mešanic v svežem in strjenem stanju smo betone uvrstili v razrede tlačne trdnosti, naredili primerjalno analizo ter podali priporočila za uporabo takih betonov pri gradnji objektov.

• Language: Slovenian
• Keywords: gradbeništvo, diplomska dela, gradbeni odpadek, recikliran agregat, beton
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [J. Resman]
• Year: 2016
• Number of pages: XVIII, 113 str., [1] str. pril.
• PID: 20.500.12556/RUL-85666
• UDC: 691.322(043.2)
• COBISS.SI-ID: 7744097
• Publication date in RUL: 14.11.2016

Secondary language

• Language: English
• Title: Influence of content and grain size distribution of recycled aggregate on concrete properties

Abstract

Environmental concerns are all around us. The influence of an increasing awareness and care for the environment is present also in construction sector, in the areas of material selection, construction technology and construction waste management. When using concrete we strive to avoid negative impacts on the environment. Legislation in the area of construction, environment and waste follows the decisions of authorities relatively fast. This year the government of the Republic of Slovenia adopted the Programme of waste management and waste prevention in the Republic of Slovenia in accordance with the legislation. The main aim of this diploma thesis is the assessment of the influence of content and grain size distribution of recycled aggregate on concrete properties. We tried to find out whether it is possible to exchange natural aggregate with a recycled one while maintaining the basic properties of fresh and hardened concrete. When preparing the concrete mixtures two types of aggregate were used. Natural aggregate was delivered from France within project "COST Action TU1404", while recycled aggregate from crushed waste concrete was acquired from a separation plant near Ljubljana. The preparation of samples and testing of recycled aggregate was carried out at the laboratory of UL FGG. With tests we first determined the physical properties of the recycled aggregate (grain size distribution, fines content, particle shape, density, water absorption, moisture content, presence of humus particles). On the basis of obtained results the suitability of the aggregate for use in concrete mixtures was assessed. Three mixtures of fresh concrete were prepared with the same amount of cement and the same water-to-cement ratio. The first mixture was prepared with fine natural aggregate and coarse recycled aggregate, the second one with recycled fine aggregate and natural coarse aggregate, while in the third mixture only recicled aggregate was used. The properties of fresh concrete (consistency, density, air content) and hardened concrete (compressive strength, splitting tensile strength, depth of water penetration under pressure) were determined according to SIST EN standard methods. On the basis of obtained results the tested concretes were classified into compressive strength classes, and analysis of the results was carried out. At the end, recommendations were given for the use of such concretes in the construction sector.

• Keywords: graduation thesis, civil engineering, construction waste, recycled aggregate, concrete