İnşaat Mühendisliği Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/395

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Subject: search.filters.subject.DuctilityWoS Q: search.filters.wosQuartile.Q1

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  • Article
    Citation - WoS: 49
    Citation - Scopus: 64
    Ductility of Frp-Concrete Systems: Investigations at Different Length Scales
    (Elsevier Sci Ltd, 2013) Lau, Denvid; Tuakta, Chakrapan; Bueyuekoeztuerk, Oral; Gunes, Oguz; Büyüköztürk, Oral
    Fiber reinforced polymer (FRP) materials have been increasingly used in the last two decades to improve various structural characteristics of reinforced concrete (RC) bridges, buildings and other structures. Ductility of the resulting FRP-concrete system plays an important role in structural performance, especially in certain applications such as earthquake resistant design of structures, where ductility and energy dissipation play a vital role. Wrapping RC columns with FRP has been shown to generally result in significant increase in ductility due to the confinement of concrete by the FRP. Other applications such as flexural strengthening of beams involve tradeoffs between ductility and the desired load capacity. Furthermore, environmental factors may adversely affect the FRP-concrete bond raising concerns about the ductility of the system due to possible premature failure modes. Characterization of these effects requires the use of more involved mechanics concepts other than the simple elastic or ultimate strength analyses. This paper focuses on characterizing ductility of the FRP-concrete systems at different length scales using a combined experimental/computational mechanics approach. Effects of several parameters on ductility, including constituent material properties and their interfaces, FRP reinforcement geometry at the macro- and meso-level, and atomistic structure at the molecular level are discussed. Integration of this knowledge will provide the basis for improved design strategies considering the ductility of FRP-concrete systems from a global as well as local perspective including interface bond behavior under various mechanical and environmental conditions. (C) 2012 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 110
    Citation - Scopus: 125
    Nano-Modification To Improve the Ductility of Cementitious Composites
    (Pergamon-elsevier Science Ltd, 2015) Yesilmen, Seda; Al-Najjar, Yazin; Balav, Mohammad Hatam; Sahmaran, Mustafa; Yildirim, Gurkan; Lachemi, Mohamed
    Effect of nano-sized mineral additions on ductility of engineered cementitious composites (ECC) containing high volumes of fly ash was investigated at different hydration degrees. Various properties of ECC mixtures with different mineral additions were compared in terms of microstructural properties of matrix, fiber-matrix interface, and fiber surface to assess improvements in ductility. Microstructural characterization was made by measuring pore size distributions through mercury intrusion porosimetry (MIP). Hydration characteristics were assessed using thermogravimetric analysis/differential thermal analysis (TGA/DTA), and fiber-matrix interface and fiber surface characteristics were assessed using scanning electron microscopy (SEM) through a period of 90 days. Moreover, compressive and flexural strength developments were monitored for the same period. Test results confirmed that mineral additions could significantly improve both flexural strength and ductility of ECC, especially at early ages. Cheaper Nano-CaCO3 was more effective compared to nano-silica. However, the crystal structure of CaCO3 played a very important role in the range of expected improvements. (C) 2015 Elsevier Ltd. All rights reserved.