20.500.12556/DKUM-92035 Combined effects of metakaolin and hybrid fibers on self-compacting concrete There is a need to develop new construction materials with improved mechanical performance and durability that are low-priced and have environmental benefits at the same time. This paper focuses on the rheological, mechanical, morphological, and durability properties of synthetic and steel fiber reinforced self-compacting concrete (SCC) containing 5–15% metakaolin (M) by mass as a green replacement for Portland cement. Testing of the fresh mixes included a slump-flow test, density, and porosity tests. Mechanical properties were determined through compression and flexural strength. A rapid chloride penetrability test (RCPT) and the chloride migration coefficient were used to assess the durability of the samples. A scanning electron microscope (SEM) with energy dispersion spectrometry (EDS) was used to study the concrete microstructure and the interfacial transition zone (ITZ). The results show that a combination of metakaolin and hybrid fibers has a negative effect on the flowability of SCC. In contrast, the inclusion of M and hybrid fibers has a positive effect on the compressive and flexural strength of SCC. The fracture of SCC samples without fibers was brittle and sudden, unlike the fiber-reinforced SCC samples, which could still transfer a considerable load with increasing crack mouth opening deflection. Overall, the chloride migration coefficients were reduced by up to 71% compared to the control mix. The chloride reduction is consistent with the resulting compact concrete microstructure, which exhibits a strong bond between fibers and the concrete matrix. self-compacting concrete synthetic and steel fibers metakaolin rheology mechanical properties chloride penetration SEM-EDS jeklena vlakna samozgoščevalni beton sintetična vlakna reologija mehanske lastnosti true false true MDPI Angleški jezik Slovenski jezik https://www.mdpi.com/journal/materials © 2022 by the authors Članek v reviji 2025-03-12 14:37:42 2025-03-12 14:37:42 2025-03-13 03:12:45 0000-00-00 00:00:00 2022 0 0 19 str. iss. 16 Vol. 15 15 Avg. 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2022-07-11 2022-08-12 2022-08-15 66.02 118750979 10.3390/ma15165588 1996-1944 materials-15-05588-v2.pdf materials-15-05588-v2.pdf 1 7740405E999BD54BBCA97A2A6EEFA666 1641f505abbb6e05ab68ad4c94eae14f43c2450d198d9c8f39bbb9d427174919 f77b671d-ff47-11ef-9eb9-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=189210 https://www.mdpi.com/1996-1944/15/16/5588 0 fce662e1-ff47-11ef-9eb9-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=189211 Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Fakulteta za kemijo in kemijsko tehnologijo 0 0 0