20.500.12556/RUL-188236 Vpliv distančnikov na kakovost krovnega sloja betona diplomsko delo Influence of reinforcement spacers on the quality of the concrete cover Armiranobetonske konstrukcije so eden najpogosteje uporabljenih konstrukcijskih sistemov v sodobnem gradbeništvu. Njihova trajnost je med drugim odvisna od kakovosti in debeline krovnega sloja betona, katerega projektirano debelino med izvedbo zagotavljajo distančniki. Ker distančniki ostanejo trajno vgrajeni v krovnem sloju in predstavljajo lokalno diskontinuiteto, lahko vplivajo na njegove transportne lastnosti, vendar je ta vpliv še razmeroma slabo raziskan. Namen diplomske naloge je bil eksperimentalno raziskati vpliv distančnikov različnih materialov in geometrijskih oblik na lokalne transportne lastnosti krovnega sloja betona. Preizkušeni so bili trije tipi distančnikov, vgrajeni v dve različni betonski mešanici, ter referenčni preizkušanci brez distančnikov. Izvedena sta bila preskus zrakoprepustnosti krovnega sloja po SIA 262/1 in preskus globine prodora vode pod pritiskom po SIST EN 12390-8. Rezultati so pokazali, da lahko prisotnost distančnika lokalno poveča prepustnost krovnega sloja, pri čemer je bil obseg vpliva odvisen od vrste distančnika in betonske mešanice. Med preiskanimi distančniki so bile najvišje povprečne vrednosti pri obeh preskusnih metodah izmerjene pri cementnem distančniku D3. Njegov koeficient zrakoprepustnosti kT je bil glede na referenčne preizkušance približno 4-krat večji, pri betonski mešanici 2 pa je bila povprečna globina prodora vode kar 10,6-krat večja. Pri vseh treh preizkušancih te skupine je voda dosegla armaturno palico. Rezultati obeh preskusnih metod kažejo, da območje distančnika lahko predstavlja lokalno prednostno transportno pot skozi krovni sloj. Izbira distančnika zato ni zgolj izvedbena podrobnost, temveč lahko vpliva na lokalno zaščitno sposobnost krovnega sloja in posledično na trajnost armiranobetonske konstrukcije. Zaradi majhnega števila preizkušancev v posamezni skupini pa bi bilo za zanesljivejšo kvantifikacijo vpliva posameznih tipov distančnikov potrebno nadaljnje raziskovanje. Reinforced concrete structures are among the most widely used structural systems in modern construction. Their durability depends, among other factors, on the quality and thickness of the concrete cover, the specified thickness of which is ensured during construction by reinforcement spacers. Since spacers remain permanently embedded in the concrete cover and represent a local discontinuity, they may affect its transport properties; however, this influence is still relatively poorly understood. The aim of this diploma thesis was to experimentally investigate the influence of spacers of different materials and geometries on the local transport properties of the concrete cover. Three types of spacers embedded in two different concrete mixtures were tested, together with reference specimens without spacers. Air permeability of the concrete cover was tested in accordance with SIA 262/1, and water penetration under pressure was determined in accordance with SIST EN 12390-8. The results showed that the presence of a spacer can locally increase the permeability of the concrete cover, with the magnitude of the effect depending on the type of spacer and the concrete mixture. Among the tested spacers, the highest average values obtained by both test methods were measured for the cementitious spacer D3. Its air permeability coefficient kT was approximately four times higher than that of the reference specimens, while for concrete mixture 2 the average water penetration depth was as much as 10.6 times greater. In all three specimens in this group, the water reached the reinforcing bar. The results of both test methods indicate that the spacer region may act as a local preferential transport path through the concrete cover. The selection of a spacer should therefore not be regarded merely as a construction detail, as it may affect the local protective performance of the concrete cover and consequently the durability of a reinforced concrete structure. However, due to the small number of specimens in each group, further research is required to provide a more reliable quantification of the influence of individual spacer types. diplomske naloge gradbeništvo distančniki krovni sloj betona zrakoprepustnost globina prodora vode trajnost armiranega betona graduation thesis civil engineering reinforcement spacers concrete cover air permeability water penetration depth durability of reinforced concrete true false false [L. Šadl] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-09-19 08:46:13 2026-09-19 08:46:16 2026-09-21 13:37:14 0000-00-00 00:00:00 2026 0 Ljubljana 2026 Ljubljana 1 spletni vir (1 datoteka PDF (IX, 38 str., 3 str. pril.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 624.012.45:621.882.63(043.2) 182688 291843843 23207.pdf 23207.pdf 1 E59B578003F8C4F3BEBC17E1AA814935 ebf7b83dffa859a96f7e26bcd326197b8f3098aa47bc727727e834352cab00a4 c19e99bb-b3f5-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=248265 Fakulteta za gradbeništvo in geodezijo 0 0 0