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Article Citation - WoS: 148Citation - Scopus: 180Effects of Elevated Temperature on Compressive Strength and Weight Loss of the Light-Weight Concrete With Silica Fume and Superplasticizer(Elsevier Sci Ltd, 2008) Sancak, Emre; Sari, Y. Dursun; Simsek, OsmanIn this study, structural light-weight concretes produced by Pumice (LWC) and concretes with normal-weight aggregate (NWC) were investigated. Compressive strength and weight loss of the concretes were determined after being exposed to high temperatures (20, 100, 400, 800, 1000 degrees C). To achieve these objectives, 12 different types of concrete mixtures were produced. In producing the mixtures, silica fume (SF) was used to replace the Portland cement in the ratios of 0%, 5% and 10% by weight. Half of the mixtures were obtained by adding superplasticizers (SP) to the above mixtures in the ratio of 2% by weight. In conclusion; unit weight of LWC was 23% lower than that of NWC. The LWC containing 2% SP could retain 38% of the initial compressive strength. Rate of deterioration was higher in NWC when compared to LWC. The loss of compressive strengths increased depending on the ratio of using SF at about 800 degrees C and over. (C) 2008 Elsevier Ltd. All rights reserved.Article Citation - WoS: 124Citation - Scopus: 141The Effects of Gradation and Admixture on the Pumice Lightweight Aggregate Concrete(Pergamon-elsevier Science Ltd, 2005) Sari, D; Pasamehmetoglu, AGThe usage of lightweight concrete, which has some advantage over ordinary concrete, has increased to a remarkable level in recent years. Many researchers have investigated the possible uses of lightweight concrete in terms of its strength, density and other mechanical and physical properties. The desired quality for lightweight concrete can be obtained through the proper selection of admixtures and proper grading of the lightweight aggregate. In this article, an experimental investigation on the production of moderate-strength lightweight concrete with pumice, according to the ACI standard, is presented. The gradation curves' (which fall within A16-C16 gradation curves, Turkish Standard Code, TS706) performances were investigated in terms of strength and density. The addition of superplasticizer and air-entraining admixtures improved the strength-to-density ratio of the hardened concrete and the workability of fresh concrete. As a result of this study, lightweight concrete blocks having a minimum compressive strength of 6.56 N/mm(2) and a density of 1300 kg/m(3) were obtained. (c) 2004 Elsevier Ltd. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 3Comparative Performance Study of Acidic Pumice and Basic Pumice Inclusions for Acrylonitrile-Butadiene Composite Filaments(Mary Ann Liebert, inc, 2024) Tayfun, Umit; Tirkes, Seha; Dogan, Mehmet; Tirkes, Suha; Zahmakiran, MehmetThis study aims to evaluate the effective use of porous pumice powder as an additive in acrylonitrile-butadiene-styrene (ABS)-based composite materials. The influence of pumice addition on mechanical, thermomechanical, thermal, and physical properties of ABS filaments was reported. Two types of pumice, namely acidic pumice (AP) and basic pumice (BP), were melt compounded with ABS at loading levels of 5%, 10%, 15%, and 20% by weight using the melt extrusion preparation method. Composites were shaped into dog bone test specimens by the injection molding process. The physical properties of pumice powders were investigated by particle size analysis and X-ray spectroscopy techniques. Mechanical, thermomechanical, thermal, melt flow, and morphological behaviors of ABS/AP and ABS/BP composite filaments were proposed. According to test results, pumice addition led to an increase in the mechanical response of ABS up to a filling ratio of 10%. Further inclusion of pumice caused sharp reduction due to the possible agglomeration of pumice particles. Composites filled with AP yielded remarkably higher mechanical performance in terms of tensile, impact, and hardness strength compared with BP-loaded composites. According to thermal analyses, ABS exhibited higher thermal stability after incorporation of AP and BP. Pumice addition also resulted in raising the glass transition temperature of ABS. Melt flow index (MFI) findings revealed that addition of two types of pumice led to an opposite trend in the melt flow behavior of ABS filaments. Homogeneous dispersion of pumice particles into the ABS matrix when adding low amounts, as well as reduction in dispersion homogeneity with high amounts, of AP and BP was confirmed by scanning electron microscopy (SEM) micrographs.
