Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Effects of Dry Particle Coating With Nano-and Microparticles on Early Compressive Strength of Portland Cement Pastes(Tulpar Academic Publishing, 2021-12-16) Yorulmaz, Hediye; Özuzun, Sümeyye; Uzal, Burak; İLkentapar, Serhan; Durak, Uğur; Karahan, Okan; Atis, C. D.It is known that nano-and microparticles have been very popular in recent years since their advantages. However, due to the very small size of such materials, they have very high tendency to agglomeration particularly for nanoparticles. Therefore, it is critical that they are properly distributed in the system to which they are added. This paper investigated the effects of dry particle coating with nano-and microparticles to solve the agglomeration problem. For a clear evaluation, paste samples were preferred to detemine the compressive strength. Nano-SiO<inf>2</inf> and nano-CaCO<inf>3</inf>, microCaCO<inf>3</inf> and micro-SiO<inf>2</inf>, also known as silica fume, were selected as particulate additives. It was studied by the addition of various percentages (0.3, 0.7, 1, 2, 3 and 5%) of nano-and microparticles in cementitious systems, replacing cement by weight with and without dry particle coating. Dry particle coating was made by using a highspeed paddle mixer. Portland cement and additive particles were mixed at 1500 rpm for 30 seconds in high-speed powder mixer designed for this purpose. The 3-day compressive strength of the cement-based samples to which particles were added at the specified rates was determined and the effect of the dry particle coating on the early strength was investigated. According to the results, it was observed that the production of paste with the dry particle coating technique gave higher compressive strength compared to the production of paste directly in early period. Especially with dry particle coating, compressive strength increased more than 100% in paste samples containing 0.3% nano-SiO<inf>2</inf> compared to direct addition without coating. © 2024 Elsevier B.V., All rights reserved.Conference Object Citation - WoS: 30Citation - Scopus: 31Compatibility of Superplasticizers With Limestone-Metakaolin Blended Cementitious System(Springer, 2015) Zaribaf, Behnaz H.; Uzal, Burak; Kurtis, KimberleyThis study investigates the performance of polycarboxylate ether (PCE), polymelamine sulfonate (PMS), sodium lignosulfonate and naphthalene formaldehyde condensate (PNS) superplasticizers (SPs) with ASTM C595 Type IL cement (with up to 15% calcium carbonate) combined with 10 and 30 % metakaolin (MK) substitutions by mass. The required dosage of each SP for 10 % and 30 % MK substitutions were determined based on mini slump test to establish equivalent paste flow. At these dosage rates, the effects of SPs on setting time, hydration kinetics, and strength development were measured. Life cycle assessment (LCA) was carried out on different cement compositions used in this study to evaluate the greenhouse gas emissions and embodied energy of limestone-metakaolin blended cement with SP addition. While MK substitution decreases the workability of samples and shortens the setting time, this study shows that adequate dosages of a compatible type of SP can be used to compensate for these effects. Of the SPs examined, PCE and PMS are found to be more compatible, compared to PNS and sodium lignosulfonate, with limestone-metakaolin blended cements.