Istanbul Technical University

About: Istanbul Technical University is a education organization based out in Istanbul, Turkey. It is known for research contribution in the topics: Fuzzy logic & Large Hadron Collider. The organization has 12889 authors who have published 25081 publications receiving 518242 citations. The organization is also known as: İstanbul Teknik Üniversitesi & Technical University of Istanbul.

Optimisation of steel fibre reinforced concretes by means of statistical response surface method

Abstract: The objective of this research is to optimise the fracture parameters of steel fibre reinforced concretes to obtain a more ductile behaviour than that of plain concrete. The effects of the aspect ratio (L/d) and volume fraction of steel fibre (Vf) on fracture properties of concrete in bending were investigated by measuring the fracture energy (GF) and characteristic length (lch). For optimisation, three-level full factorial experimental design and response surface method were used. The results show that the effects of fibre volume fraction and aspect ratio on fracture energy and characteristic length are very significant.

Synthesis, characterization, and properties of new thermally curable polyetheresters containing benzoxazine moieties in the main chain

Abstract: High molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich reaction of 4,4′-isopropylidenediphenol (bisphenol A), formaldehyde, and 2-(2-aminoethoxy)ethanol. Polycondensation of the resulting benzoxazine dietherdiol with adipoyl chloride and terephthaloyl dichloride in the presence of triethyl amine yields the corresponding PEE with the molecular weights of 34.000 Da. The structures of the precursor diol monomer and the resulting PEEs are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H-NMR) analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry (DSC). Flexible free standing transparent films of the PEEs are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 140 and 220 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 414–420, 2008