https://hdl.handle.net/20.500.12619/3935 2026-04-05T03:00:35Z 2026-04-05T03:00:35Z Özkan, Ömer Sarıbıyık, Mehmet https://hdl.handle.net/20.500.12619/3961 2020-01-15T07:28:48Z 2013-01-01T00:00:00Z

ALKALI SILICA REACTION OF BOF AND BFS WASTES COMBINATION IN CEMENT Özkan, Ömer; Sarıbıyık, Mehmet This study reports the results of an experimental study conducted to determine composite cements manufactured with the combination of Basic Oxygen Furnace (BOF) Slag and Blast Furnace Slag (BFS). The overall objective of this work is to determine whether a combination of BOF slag and BFS can be used as a cementations material to produce Composite Portland Cement (CPC). Three groups of cement are produced for testing. The first group contains BOF slag, the second group contains BFS and the last group contains the mixture of BOF slag and BFS together. Physical properties and Alkali Silica Reaction (ASR) of these groups are also evaluated in this study. Maximum ASR expansion is observed from the sample of CPC created with BOF slag. On the other hand minimum ASR expansion value is located in the sample of CPC created with BFS only.

2013-01-01T00:00:00Z Özkan, Filiz Özkan, Ömer https://hdl.handle.net/20.500.12619/3963 2020-01-15T07:28:48Z 2013-01-01T00:00:00Z

Eco-efficiency of the world cement industry and innovations: panel causality data analysis Özkan, Filiz; Özkan, Ömer Since the cement industry emits large amounts of greenhouse gases into the atmosphere, the sector is recently under scrutiny. This study empirically investigates the co-integration and the causality relationships between the carbon dioxide emissions (CO2) and the cement industries for the panel comprised of 109 countries using time series data for the period between 1995 and 2008. For the purpose of co-integration, the error correction model (ECM) and panel causality tests were applied in order to determine the aforementioned relation. Cement production was determined to be co-integrated with CO2 emissions. In the present study, the newly industrialised countries that execute 70% of the world cement production were determined to significantly affect the CO2 emissions, whereas the effect of advanced developed countries on the emissions were strikingly lower, due to the renewal of their production technologies.

2013-01-01T00:00:00Z Özkan, Ömer https://hdl.handle.net/20.500.12619/3958 2020-01-15T07:28:48Z 2009-01-01T00:00:00Z

Physical and mechanical properties of composite cements Özkan, Ömer This paper reports on the results of an experimental study conducted to evaluate the physical properties and strength development of composite cements manufactured with a steel slag (SS) and blast-furnace slag (BFS) combination. The influence of the proportions and fineness of the slag on the compressive strength of the cement blends are presented. Test results showed that the physical properties of the composite Portland cement series were affected by the BFS-SS substitution. The BFS-SS combination used for replacement gave better results when they were ground finer than the Portland cement clinker. The increase in Blame fineness of the BFS-SS combination had a positive effect on the compressive strength. The Substitution ratio can be raised to 60 to 80% provided the slag fineness value is 4600 cm(2)/g.

2009-01-01T00:00:00Z Özkan, Ömer https://hdl.handle.net/20.500.12619/3959 2020-01-15T07:28:48Z 2011-01-01T00:00:00Z

Influence of high temperature on the properties of concretes made with industrial by-products as fine aggregate replacement Özkan, Ömer Influence of high temperature on the properties of concrete containing non-ground granulated blast-furnace slag (GBFS) and coal bottom ash (BA) as fine aggregate was presented. Six series of concrete mixtures were prepared by partially replacing fine aggregate separately with GBFS and BA. Replacement percentages were between 10 and 50% with an increment of 10% by dry weight of fine aggregate. Then 0.2% polypropylene fibres (PP) were added to last three mixtures that has the same mixture with the first three series. The first series is control concrete, the second series contained GBFS and the third series contained BA. All the concrete specimens were exposed to 800 degrees C temperature at the age of 90 days. Tests were conducted to determine loss in weight, compressive strength, and dynamic modulus of elasticity. Also surface crack observations were conducted with microscope. Test results showed that it is possible to partially replace fine aggregate with GBFS or BA even if such concretes were to be subjected to high temperature response. Performance of BA concrete was found to be better than GBFS as replacement material. (C) 2010 Elsevier Ltd. All rights reserved.

2011-01-01T00:00:00Z