Yazar "Karahan, Okan" için listeleme
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Characterizing boron-enhanced one-part alkaline-activated mortars: Mechanical properties, microstructure and environmental impacts
Örklemez, Ezgi; İlkentapar, Serhan; Durak, Ugur; Gülçimen, Sedat; Uzal, Niğmet; Uzal, Burak; Karahan, Okan; Atiş, Cengiz Duran (ELSEVIER, 2024)Since alkali activators negatively effect the environmental impact assessment, it is necessary to develop the alternative activators from natural sources with low environmental impact. Therefore, in this study, the usage ... -
Comparison of Mechanical and Physical Properties of Screed with and without Expanded Polystyrene (EPS) Particles
Kılıç, Fikret Merih; Yorulmaz, Hediye; Özuzun, Sümeyye; Durak, Uğur; İlkentapar, Serhan; Karahan, Okan; Atiş, Cengiz Duran (YILDIZ TEKNİK ÜNİVERSİTESİ, 2022)In this study, in order to observe the mechanical and physical properties of ordinary screed, sandy-lightweight screed and lightweight screed samples, expanded polystyrene (EPS) was used as fine aggregate and lightweight ... -
Dual effectiveness of freezing-thawing and sulfate attack on high-volume slag-incorporated ECC
Ozbay, Erdogan; Karahan, Okan; Lachemi, Mohamed; Hossain, Khandaker M. A.; Atis, Cengiz Duran (ELSEVIER SCI LTD, 2013)This study investigated the dual effect of freeze–thaw cycles with sodium sulfate solution on the performance of non-air-entrained Engineering Cementitious Composites (ECCs) with high volumes of slag. ECC specimens ... -
Effect of Nano-SiO2 on Strength and Hydration Characteristics of Ternary Cementitious Systems
Yorulmaz, Hediye; Uzal, Burak; Karahan, Okan; Durak, Uğur; İlkentapar, Serhan; Atiş, Cengiz Duran (Institute for Ionics, 2023)This paper shows results of laboratory study on the effects of nano-SiO2 on Portland cement-fly ash systems. It is aimed to improve performance of fly ash–cement systems, particularly at early age, with the inclusion of ... -
Effects of dry particle coating with nano- and microparticles on early compressive strength of portland cement pastes
Yorulmaz, Hediye; Uzal, Burak; Özuzun, Sümeyye; İlkentapar, Serhan; Durak, Uğur; Karahan, Okan; Atiş, Cengiz Duran (Tulpar Academic Publisher, 2021)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 ... -
Fresh, Mechanical, Transport, and Durability Properties of Self-Consolidating Rubberized Concrete
Karahan, Okan; Ozbay, Erdogan; Hossain, Khandaker M. A; Lachemi, Mohamed; Atis, Cengiz Duran (AMER CONCRETE INST, 2012)This paper presents the fresh, mechanical, transport, and durability performances of self-consolidating rubberized concretes (SCRCs). Fresh concrete properties were determined with slump flow, V-funnel, J-ring, and L-box ... -
Influence of admixtures on the properties of alkali-activated slag mortars subjected to different curing conditions
Bilim, Cahit; Karahan, Okan; Atis, Cengiz Duran; Ilkentapar, Serhan (ELSEVIER SCI LTD, 2013)This paper presents the influence of shrinkage-reducing (SHR) and superplasticizing and set-retarding admixtures (SSRe) on the properties of slag pastes and mortars activated by liquid sodium silicate with different ... -
The influence of cement kiln dust on strength and durability properties of cement-based systems
Hakkomaz, Hadiye; Yorulmaz, Hediye; Durak, Uğur; İlkentapar, Serhan; Karahan, Okan; Atiş, Cengiz Duran (SPRINGER, 2022)There are very few studies in the literature on the usage of CKD in cementitious systems. This article presents the laboratory study results on the infuence of cement kiln dust (CKD) on the properties of mortar made with ... -
Influence of nano SiO2 and nano CaCO3 particles on strength, workability, and microstructural properties of fly ash-based geopolymer
Durak, Ugur; Karahan, Okan; Uzal, Burak; Ilkentapar, Serhan; Atis, Cengiz Duran (ERNST & SOHN, ROTHERSTRASSE 21, BERLIN, DEUTSCHLAND 10245, GERMANY, 2020)The influence of nano SiO2(NS) and CaCO3(NC) particles on the properties of class F fly ash based geopolymer mortar activated with different sodium ion concentrations have been investigated. Mortar mixture proportions were ... -
The infuence of cement kiln dust on strength and durability properties of cement‑based systems
Hakkomaz, Hadiye; Yorulmaz, Hediye; Durak, Ugur; Ilkentapar, Serhan; Karahan, Okan; Atis, Cengiz Duran (SPRINGER HEIDELBERG, 2022)There are very few studies in the literature on the usage of CKD in cementitious systems. This article presents the laboratory study results on the infuence of cement kiln dust (CKD) on the properties of mortar made with ... -
Investigation of Properties of Engineered Cementitious Composites Incorporating High Volumes of Fly Ash and Metakaolin
Ozbay, Erdogan; Karahan, Okan; Lachemi, Mohamed; Hossain, K. M. A.; Atis, Cengiz Duran (AMER CONCRETE INST, 2012)This study was carried out to develop engineered cementitious composites (ECCs) incorporating binary blends of high volumes of fly ash (FA) and metakaolin (MK) for the purpose of achieving low drying shrinkage and high ... -
Nanotanecikler İçeren Yüksek Miktarda Doğal Puzolan Katkılı Çimentolar: Özellikler, Hidratasyon ve Hamur İç Yapısı
Uzal, Burak; Korkanç, Mustafa; Karahan, Okan (TUBİTAK, 2015)Çimento sektörü dünya genelinde atmosfere salınan CO2 gazının %7’sinden tek başına sorumludur. Çimento sektörü odaklı CO2 emisyonlarının azaltılabilmesinde en etkin yol, çimentolardaki mineral katkı kullanım oranının ... -
A new parameter influencing the reaction kinetics and properties of fly ash based geopolymers: A pre-rest period before heat curing
Durak, Ugur; Ilkentapar, Serhan; Karahan, Okan; Atis, Cengiz Duran (ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2021)In this study, the influence of a pre-rest period before heat curing (as a new parameter), on the physical properties, flexural and compressive strength, and microstructure of geopolymer mortars and pastes produced with ... -
Reaction kinetics and properties of pumice-based geopolymer systems cured at room temperature
Küçükyıldırım, Enver; Yorulmaz, Hediye; Durak, Uğur; İlkentapar, Serhan; Uzal, Burak; Karahan, Okan; Atis, Cengiz Duran (ELSEVIER, 2023)This research investigated the kinetics of pumice-based geopolymer systems and their physical and mechanical properties. The effect of the Na2SiO3/NaOH ratio of geopolymer systems on the rate of heat evolution and total heat ...
