Yazar "Severcan, M. H." seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe EVALUATION OF THE RELATIONSHIPS BETWEEN THE STRENGTH PROPERTIES OF HSC CONTAINING SF AND GP AT A LOW WATER-BINDER RATIO(SPRINGER INTERNATIONAL PUBLISHING AG, 2015) Saridemir, M.; Severcan, M. H.; Ciflikli, M.; Acer, S.In this paper, the effect of high strength concrete (HSC) manufactured with silica fume (SF) and ground pumice (GP) is investigated. Portland cement was replaced with SF, GP and combination of SF and GP up to 25%. 22 different concrete mixtures with these replacement ratios were produced by using 0.25 water-binder ratio. The ultrasound pulse velocity, compressive, splitting tensile and flexural strengths of these concretes were determined. The experimental results show that producing HSC is feasible with SF and GP. Besides, the experimental results indicate that SF and SF in combination with GP can enhance both the short-term and the long-term properties of concrete, whereas GP needs a comparatively longer time to obtain a suitable effect. The results are also supported by scanning electron microscope analysis. The optimum replacement ratios of SF and GP are found to be 15% and 5% of cement, respectively. The relationships between ultrasound pulse velocity, compressive, splitting tensile and flexural strengths are investigated by considering the effects of SF and GP.Öğe The influence of elevated temperature on strength and microstructure of high strength concrete containing ground pumice and metakaolin(ELSEVIER SCI LTD, 2016) Saridemir, M.; Severcan, M. H.; Ciflikli, M.; Celikten, S.; Ozcan, F.; Atis, C. D.A laboratory study is performed to evaluate the influence of elevated temperature on the strength and microstructural properties of high strength concretes (HSCs) containing ground pumice (GP), and blend of ground pumice and metakaolin (MK) mixture. Twelve different mixtures of HSCs containing GP and MM were produced, water-to-binder ratio was kept constant as 0.20. Hardened concrete specimens were exposed to 250 degrees C, 500 degrees C and 750 degrees C elevated temperatures increased with a heating rate of 5 degrees C/min. Ultrasound pulse velocity (U-pv), compressive strength (f(c)), flexural strength (f(fs)) and splitting tensile strength (f(sts)) values of concrete samples were measured on unheated control concrete and after air-cooling period of heated concrete. The crack formation and alterations in the matrix, interface and aggregate of HSCs were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and polarized light microscope (PLM) analyses. XRD, SEM and PLM analyses have shown that, increasing target temperature result with decrease in mechanical properties i.e. U-pv, f(c), f(fs) and f(sts) values. Elevated temperature also results with crack formation, and increasing target temperature caused more cracks. Alterations in the matrix, interface and aggregate were, also observed by these analyses. The experimental results indicate that concrete made with MK + GP blend together as a replacement of cement in mass basis behaved better than control concrete made with cement only, and concrete containing only GP as a cement replacement. (C) 2016 Elsevier Ltd. All rights reserved.Öğe The use of discontinuous first and second-order mixed boundary elements for 2D elastostatics(TECHNO-PRESS, 2010) Severcan, M. H.; Tanrikulu, A. K.; Tanrikulu, A. H.; Deneme, I. O.In classical higher-order discontinuous boundary element formulation for two-dimensional elastostatics, interpolation functions for different boundary variables (i.e., boundary displacements and tractions) are assumed to be the same. However, there is a derivational relationship between these variables. This paper presents a boundary element formulation, called Mixed Boundary Element Formulation, for two dimensional elastostatic problems in which above mentioned relationship is taking into account. The formulations are performed by using discontinuous first and second-order mixed boundary elements. Based on the formulations presented in this study, two computer softwares are developed and verified through some example problems. The results show that the present formulation is credible.Öğe Use and comparison of different types of boundary elements for 2D soil-structure interaction problems(ELSEVIER SCI LTD, 2009) Deneme, I. O.; Yerli, H. R.; Severcan, M. H.; Tanrikulu, A. H.; Tanrikulu, A. K.In this study, the usage and the comparison of some discontinuous boundary elements (constant, linear and quadratic) are investigated for 2D soil-structure interaction (SSI) problems. Based on the formulations presented in this study, some general purpose computer programs coded in FORTRAN77 are developed for each type of discontinuous boundary elements for elastic or visco-elastic 2D SSI problems. The programs perform the analysis in Fourier transform space. The results of 2D dynamic SSI problems are compared with those in the literature. Examples studied here indicate that present formulations have sufficient computational accuracy for analyzing 2D SSI problems. As a result of this study, the use of constant element is more sufficient than the other type of elements. (C) 2009 Elsevier Ltd. All rights reserved.
