Browsing by Author "Yesilmen, S."

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Citation - WoS: 47
Citation - Scopus: 59
Physical and Chemical Actions of Nano-Mineral Additives on Properties of High-Volume Fly Ash Engineered Cementitious Composites
(Amer Concrete inst, 2016) Al-Najjar, Y.; Yesilmen, S.; Al-Dahawi, Majeed; Sahmaran, M.; Yildirim, G.; Lachemi, M.; Amleh, L.; 17729; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Unlike conventional concrete, the material design process for engineered cementitious composites (ECC) involves micromechanics-based design theory, paving the way for the use of high volumes of fly ash (HVFA) as a major component. Using high volumes of fly ash (up to 85% weight fraction of cement) in ECC mixtures enables improved tensile ductility (approximately a 3% increase in long-term tensile strain) with reduced crack widths, although it also leads to significantly reduced early-age compressive and tensile strength and chloride ion resistance. However, nanomineral additives are known to improve mechanical strength and durability of HVFA systems. The study emphasizes the effects of different fly ash (FA)/cement ratios on various properties (hydration and microstructural characteristics, transport and mechanical properties) of ECC mixtures designed with different mineral additives. Experimental results confirm that although different optimum levels can be selected to favor various ECC properties, optimum weight fraction of FA is dependent on the mechanism of nanomodification (that is, type of modifier). The optimum level of fly ash weight fraction that yields the highest rate of improvement through nanomodification of ECC varies for different mechanical and transport properties.
Citation - Scopus: 3
Strength Prediction of Engineered Cementitious Composites With Artificial Neural Networks
(MIM RESEARCH GROUP, 2021) Yesilmen, S.; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Engineered Cementitious composites (ECC) became widely popular in the last decade due to their superior mechanical and durability properties. Strength prediction of ECC remains an important subject since the variation of strength with age is more emphasized in these composites. In this study, mix design components and corresponding strengths of various ECC designs are obtained from the literature and ANN models were developed to predict compressive and flexural strength of ECCs. Error margins of both models were on the lower side of the reported error values in the available literature while using data with the highest variability and noise. As a result, both models claim considerable applicability in all ECC mixture types. © 2021 MIM Research Group. All rights reserved.