Yayınlar
Koleksiyondaki öğeler
- MakaleYalnız künye2010Scopus SJRQ3Natural convection in a triangular cross section roof under daylight conditions
Küçük, Haydar; Gedikli, Hasan
The natural convection is numerically investigated in a roof of triangular cross section under constant heat flux with seven different values depending on daylight on the inclined wall, constant wall temperature on the bottom wall and adiabatic on the vertical wall boundary conditions. Continuity, momentum and energy equations are solved by using fmite volume method for laminar, two-dimensional and steady-state regime. Streamlines, isothenns, local and mean Nusselt numbers are p̧resented for AR=0.25, 0.5, 0.75 and 1.0 and Ra=103, 104, 105, 106. The amount of heat flux ranges from 163 W/m2 to 808 W/m2 depending on daylight and the Prandtl number is chosen as 0.7. It is found out that the aspect ratio and Rayleigh number highly affect the heat transfer on the bottom and inclined walls while heat flux slightly affects.
AtıfScopus1WoS1
İncele - BildiriYalnız künye2014Approximation of the inverse elliptic problem with mixed boundary value conditions
Ashyralyyev, Charyyar; Dedeturk, Mutlu
The inverse problem for the multidimensional elliptic equation with Neumann-Dirichlet conditions are presented. For the approximate solution of this inverse problem the first and second order of accuracy in t and in space variables difference schemes are constructed. The stability, almost coercive stability and coercive stability estimates for the solution of these difference schemes are obtained. The algorithm for approximate solution is tested in a two-dimensional inverse problem.
AtıfScopus4WoS4OpenAlex5İncele - MakaleYalnız künye2013Scopus SJRQ1The contribution of hydropower in meeting electric energy needs: The case of Turkey
Akpinar, Adem
In this article, an attempt is made to better understand the contribution of hydropower in meeting electric energy needs of Turkey. Thus, a comparison between Turkey and other countries, which have some similarities with Turkey or which are more developed nations compared to Turkey, for evaluating from different aspects the contribution of hydropower in meeting electric energy needs is performed. The producers of electricity and hydroelectricity in the world, and the electric sectors of all the selected countries are firstly examined. Thereafter, Turkey's water resources and its potential, hydropower potential, and current status of hydropower in Turkey are investigated in detail. A detailed discussion regarding economic and energy indicators, hydroelectricity versus thermal electricity, the contributions of hydroelectricity to the total and renewable electricity generation, and the usage status of hydro potential of each selected nation is also made. Finally, it is found that hydropower is the second largest contributor in meeting Turkey's electric energy needs after thermal, mainly natural gas. It is also estimated that the contribution of hydropower will continue because a vast amount of its economically feasible hydro potential (about 64%) is undeveloped. Besides, it is determined that the contribution of hydropower in the total electricity generation in Turkey is greater than that of China and India, but it is lower than that of Norway, Brazil, and Canada.
AtıfScopus21WoS20OpenAlex27İncele - MakaleYalnız künye2014Scopus SJRQ2Assessment of kinetics, thermodynamics and equilibrium parameters of Cr(VI) biosorption onto Pinus brutia Ten
Ozdes, Duygu; Gundogdu, Ali; Kemer, Baris; Duran, Celal; Kucuk, Murat; Soylak, Mustafa
The aim of the present study was to investigate the sorption potential of pine bark (Pinus brutia Ten.) for removal of Cr(VI) ions from aqueous solutions. The biosorption characteristics of Cr(VI) ions onto bark biomass were examined with respect to the changes in initial pH of the solution, contact time, initial Cr(VI) and bark concentration, bark particle size, temperature, etc. The biosorption isotherms were described by means of Langmuir and Freundlich models and the biosorption kinetics were analysed using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The thermodynamic parameters proved that the process was feasible, spontaneous and endothermic in nature.
AtıfScopus34WoS29İncele - MakaleYalnız künye2015Scopus SJRQ4Genetic characterization of the Akkaraman, Morkaraman and Karayaka sheep through microsatellite variation
Das, Huseyin; Turan, Ibrahim; Demir, Selim
Genotypes have to be controlled periodically and necessary precautions should be taken in order to ensure that animal biodiversity is not lost. In this study, the genotypes of the Akkaraman, Karayaka and Morkaraman species from among Turkey’s local sheep were examined at 7 different microsatellite loci. The average allele counts are close to each other and were determined as 8,905±0,483. Whereas the PIC values ranged from between 0,507-0,794 at an average of 0,705. The He and Ho values used to calculate genetic diversity were determined on average as 0,734±0,023 and 0,509±0,038 respectively. According to the Fisher-Exact test result, the populations are not in HWE (P<0.001). Whereas the FIS values that show inter- population genetic diversity were determined as 0,353±0,092 (KRY), 0,328±0,095 (MRK) and 0,237±0,059 (AKK) respectively. In addition, Population Assignment and Principal Coordinate Analysis graphs were formed. When the pairwise FST and Nm, NeiuD,SHUA and G Statistics values used to calculate the genetic similarities and differences are examined, it is observed that the closest relations in terms of genetics is among AKK-KRY followed respectively by AKK-MRK and KRY-MRK.
AtıfScopus5WoS5OpenAlex4İncele - MakaleAçık Erişim2015Scopus SJRQ2Chemical composition of oleoresin and larvae gallery resin of pinus brutia attacked by dioryctria sylvestrella ratz; [Kemijski sastav oleorezina i smole galerije ličinki sa stabla bora (pinus brutia) napadnutoga insektima dioryctria sylvestrella ratz]
Öz, Mehmet; Deniz, İlhan; Okan, Onur Tolga; Said Fidan, M.
Dioryctria sylvestrella Ratz. poses a remarkable hazard for the Pinus brutia Ten. in Turkey. In the current study, the larvae gallery resin of five trees and essential oils of resin, which was obtained with the AcidPaste Method, were analyzed using the Gas Chromatography and Mass Spectrometry (GC-MS) Method. Thirty nine compounds were found in larvae gallery resin, which were produced by Dioryctria sylvestrella Ratz, while thirty six compounds were extracted from oleoresin obtained by the Acid-Paste Method. The most common compounds of larvae gallery resin were α-pinene at a rate of 20.2%, β-caryophyllen at a rate of 10.8%, γ-terpinene at a rate of 10.1% and β-pinene at a rate of 9.4 percent. The most common compounds of oleoresin were α-pinene at a rate of 19.7%, β-pinene at a rate of 13.3%, γ-terpinene at a rate of 10.2% and β-caryophyllen at a rate of 7.8 percent. Also, the quantities of some compounds within larvae gallery resin such as β-pinene, limonene, and sylvestrene decreased compared to those of oleoresin, while the quantities of some compounds in oleoresin including α-longipinene, α-terpineol, and longifolene increased compared to that of larvae gallery resin. However, no qualitative difference was found.
AtıfScopus7WoS8OpenAlex11İncele - MakaleYalnız künye2012Scopus SJRQ2Determination of water level effects on the dynamic characteristics of a prototype arch dam model using ambient vibration testing
Sevim, B.; Bayraktar, A.; Altunişik, A.C.; Adanur, S.; Akköse, M.
This study investigated the water level effects on the dynamic characteristics of a prototype arch dam model using ambient vibration testing were investigated. Achievement of this purpose involved construction of a prototype arch dam-reservoir-foundation model under laboratory. The dam body was constructed with 60 cm height. Ambient vibration tests on the arch dam estimated its natural frequencies, mode shapes and damping ratios for different water levels. In the ambient vibration tests, ambient excitations are provided from small impact effects and the responses of the arch dam are measured. It can be stated from the study that natural frequencies are not overly changed among 0-30 cm water levels; however they are increased for higher water levels. The difference between the first natural frequencies of the arch dam obtained from empty reservoir (H = 0 cm) and full reservoir (H = 60 cm) is about 20-25%.
AtıfScopus24WoS21OpenAlex29İncele - MakaleAçık Erişim2013Scopus SJRQ1The genesis of the slab window-related Arzular low-sulfidation epithermal gold mineralization (eastern Pontides, NE Turkey)
Akaryali, Enver; Tüysüz, Necati
The Arzular mineralization is one of the best examples of epithermal gold deposits in the eastern Pontides orogenic belt. The mineralization is hosted by the subduction-related basaltic andesites and is mainly controlled by E-W and NE-SW trending fracture zones. The main ore minerals are galena, sphalerite, pyrite, chalcopyrite, tetrahedrite and gold. Homogenization temperatures of fluid inclusions are between 130 and 295 C for quartz and between 90 and 133 C for sphalerite. Sulphur isotope values obtained from pyrite, galena and sphalerite vary between -1.2‰ and 3‰, indicating that sulphur belongs to magmatic origin and was derived from the Lutetian non-adakitic granitic intrusions in the region. Oxygen isotope values are between 15.0‰ and 16.7‰, and hydrogen isotope values are between -87‰ and -91‰. The sulphur isotope thermometer yielded temperatures in the range of 244-291 C for the ore formation. Our results support the hypothesis that the Arzular mineralization is a low-sulfidation epithermal gold deposit associated with non-adakitic subduction-related granitic magmas that were generated by slab window-related processes in a south-dipping subduction zone during the Lutetian.
AtıfScopus25WoS19OpenAlex29İncele - MakaleAçık Erişim2015Scopus SJRQ2Investigate the effects of non-genetic factors on calving difficulty and stillbirth rate in holstein friesian cattle using the CHAID analysis; [Genetiksel Olmayan Faktörlerin Siyah Alaca Sığırlarda Güç ve Ölü Doğuma Etkilerinin CHAID Analizi İle İncelenmesi]
Bayram, Bahri; Topal, Mehmet; Aksakal, Vecihi; Önk, Kadir
A total number of 947 calving records from 613 Holstein Friesian cows raised at a private dairy farm in Kelkit, Turkey, from 2004 to 2006 were used to study the effect of non-genetic factors on calving difficulty and stillbirth rate using CHAID algorithm. The mean calf birth weight was 41.0±0.19 kg. The overall incidence of calving difficulty and stillbirths in the Holstein Friesian herd were 9.1% and 9.4%, respectively. Calf birth weight, birth type and calving season had the greatest impact on calving difficulty. The increase in calf birth weight was associated with a significant increase in calving difficulties (P<0.01). The calving difficulty risk in twins (18.9%) was higher than in singleton calves (5.0%). The main environmental variables affecting the stillbirth rate were parity number, calf birth weight, sex of calf, calving season and calving difficulty. Parity number was statistically the most relevant factor affecting the stillbirth rate, which was also higher in primiparous (18.7%) than in multiparous cows (5.4%). As the calf birth weight increased, a significant increase was also in the stillbirth rate (P<0.01). The stillbirth rate in winter (19.7%) was higher than in other seasons (3.6%) (P<0.01). Calving assistance was associated with an increased risk of stillbirth (P<0.05). As a result, calf birth weight, birth type and calving season had the greatest impact variables on calving difficulty, however, parity, calf birth weight, sex, calving season and calving difficulty were the most effective variables on stillbirth in Holstein Friesian Cattle.
AtıfScopus8WoS8OpenAlex1İncele - MakaleYalnız künye2014Scopus SJRQ2Influence of wall flexibility on dynamic response of cantilever retaining walls
Cakir, Tufan
A seismic evaluation is made of the response to horizontal ground shaking of cantilever retaining walls using the finite element model in three dimensional space whose verification is provided analytically through the modal analysis technique in case of the assumptions of fixed base, complete bonding behavior at the wall-soil interface, and elastic behavior of soil. Thanks to the versatility of the finite element model, the retained medium is then idealized as a uniform, elastoplastic stratum of constant thickness and semi-infinite extent in the horizontal direction considering debonding behavior at the interface in order to perform comprehensive soil-structure interaction (SSI) analyses. The parameters varied include the flexibility of the wall, the properties of the soil medium, and the characteristics of the ground motion. Two different finite element models corresponding with flexible and rigid wall configurations are studied for six different soil types under the effects of two different ground motions. The response quantities examined incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that the wall flexibility and soil properties have a major effect on seismic behavior of cantilever retaining walls and should be considered in design criteria of cantilever walls. Furthermore, the results of the numerical investigations are expected to be useful for the better understanding and the optimization of seismic design of this particular type of retaining structure.
AtıfScopus16WoS16OpenAlex18İncele - MakaleYalnız künye2012Scopus SJRQ1Wave energy potential along the south-east coasts of the Black Sea
Akpinar, Adem; Kömürcü, Murat Ihsan
This study aims to assess and characterize wave energy resource along the southeastern coasts of the Black Sea. For this purpose, wave energy potential was investigated at a total of 7 study points in this area. The potential for energy generation was assessed based on six-hourly data from a third generation wave model (SWAN) covering the period 1995-2009. The results were validated with buoy measurements and wave energy and power was calculated with the numerical hindcast data. For characterization of wave energy potential, average annual and seasonal variations of the wave power in this area was firstly investigated. Second, wave energy development indexes and the probabilities of exceedance of wave power at the study points were determined. Third, wave energy resource in different ranges of significant wave heights and zero-crossing periods were characterized. Finally, It was found that annual wave energy of all points except Sinop point, whose annual wave energy is 10 MWh/m, is approximately 6 MWh/m and the bulk of annual wave energy occurs for significant wave heights between 0.5 and 2 m and periods between 2 and 5 s.
AtıfScopus86WoS81OpenAlex87İncele - MakaleYalnız künye2014Scopus SJRQ2Exergetic analysis of using the gaseous fuels in spark ignition engines
Sezer, Ismet; Bilgin, Atilla
This paper aims to investigate the use of alternative gaseous fuels in spark ignition engines via an exergy analysis. A quasi-dimensional two-zone thermodynamic cycle model is used for this purpose. The intake and exhaust processes are computed by a simple approximation method, and the processes (that is, compression, combustion, and expansion) are simulated in detail. The turbulent flame propagation process is used for the combustion simulation. The second law of thermodynamics is applied to the cycle model to perform the exergy analysis. The exergy transfers associated with heat, work, and exhaust; the irreversibilities, thermomechanical exergy, fuel chemical exergy, and total exergy have been computed in the exergy analysis. A distribution of the fuel exergy, the energy-based (the first law) efficiency, and the exergetic (the second law) efficiency were also calculated during the exergy analysis. Thus, the effects of using natural gas and liquefied petroleum gas on the exergetic terms and the efficiencies are investigated. The results of the study show that investigated alternative gaseous fuels have affected the variations in the exergy transfers, irreversibilities, and efficiencies. The gaseous fuels are suitable from the exergy point of view because of the lessened exergy destruction rate, but they suffer from the engine performance reduction.
AtıfScopus3WoS1OpenAlex3İncele - MakaleAçık Erişim2015Scopus SJRQ2Static and dynamic responses of Halgavor footbridge using steel and FRP materials
Gunaydin, M.; Adanur, S.; Altunisik, A.C.; Sevim, B.
In recent years, the use of fiber reinforced polymer composites has increased because of their unique features. They have been used widely in the aircraft and space industries, medical and sporting goods and automotive industries. Thanks to their beneficial and various advantages over traditional materials such as high strength, high rigidity, low weight, corrosion resistance, low maintenance cost, aesthetic appearance and easy demountable or moveable construction. In this paper, it is aimed to determine and compare the geometrically nonlinear static and dynamic analysis results of footbridges using steel and glass fiber reinforced polymer composite (GFRP) materials. For this purpose, Halgavor suspension footbridge is selected as numerical examples. The analyses are performed using three identical footbridges, first constructed from steel, second built only with GFRP material and third made of steel-GFRP material, under static and dynamic loadings using finite element method. In the finite element modeling and analyses, SAP2000 program is used. Geometric nonlinearities are taken into consideration in the analysis using P-Delta criterion. The numerical results have indicated that the responses of the three bridges are different and that the response values obtained for the GFRP composite bridge are quite less compared to the steel bridge. It is understood that GFRP material is more useful than the steel for the footbridges.
AtıfScopus12WoS12OpenAlex9İncele - MakaleYalnız künye2015Scopus SJRQ3The effects of land use type on soil erodibilty indices in Galyan-Atasu Dam Watershed, Trabzon, N.E. Turkey
Yilmaz, Murat; Usta, Ayhan; Çakir, Günay; Kahveci, Seda Nur Ince
Erodibility indices together with other soil properties of Atasu Dam watershed in Trabzon, Turkey, were analyzed according to land use regimes (grassland, cultivated land, coniferous forest land and broadleaf forest land) and the granite parent material from which the soil develops. The findings could be applied to future management plans with the aim of enhancing the ability of Atasu Dam to supply water for drinking, domestic use and irrigation to the region. Forty sample plots having the same northern aspect were selected from bordering lands. Cross-section soil samples from depth levels of 0-10 cm and 10-30 cm were gathered from the selected sites. Particle size distribution, soil organic matter (SOM), dispersion ratio (DR), erosion ratio (ER), colloid-moisture equivalent ratio (C-MER), structural stability index (SSI), water dispersible clay (WDC), clay dispersion ratio (CDR), clay flocculation index (CFI), exchangeable cations, exchangeable sodium ratio (ESR), sodium adsorption ratio (SAR) and soil reaction (pH) analyses were performed. A variance analysis was carried out in order to determine if the obtained results varied according to land use type. Soil samples from a variety of sites in areas with granite as parent material were applied to erodibility indices and the sites were found to be susceptible to erosion. Some other characteristics were also found to be effective on the erodibility indices, including the relationship of soil organics, which was also considered to be to a factor of interest in this study. Soils that were developed from granite parent material in areas covered by forest were observed to be more susceptible to erosion. These results were fairly significant in the context of the study area of the Galyan-Atasu Dam watershed. This study suggests that incorporating these findings in planning and management-related activities can potentially lead to improvement of the basin and contribute to the economic life of the dam.
AtıfScopus5WoS7İncele - MakaleYalnız künye2015Scopus SJRQ1Probiotic butter: Stability, free fatty acid composition and some quality parameters during refrigerated storage
Erkaya, Tuba; Ürkek, Bayram; Doğru, Ünsal; Çetin, Bülent; Şengül, Mustafa
This study was carried out to determine whether butter can be a carrier for probiotics by observing the survivability of selected probiotic strains during cold storage. The effects of using probiotic adjunct cultures (Lactobacillus acidophilus ATCC 4356 and Bifidobacterium bifidum ATCC 29521) in butter on microbiological counts, sensory characteristics, chemical characteristics and free fatty acid (FFA) composition during storage for 60 days were investigated. The butter samples produced with B. bifidum ATCC 29521 maintained the probiotic characteristics, in that the level of viable cells of the probiotic was >106 cfu g-1 until 30 days of storage. The highest scores in sensory assessment were obtained on the first day of storage. FFAs, including C2:0, C6:0, C14:0 and C18:1, were affected significantly by storage period and by the adjunct cultures, however conjugated linoleic acid and C18:2 were not affected by storage period and the use of probiotic adjunct culture.
AtıfScopus44WoS34OpenAlex42İncele - MakaleAçık Erişim2015Scopus SJRQ3Barley flour addition decreases the oil uptake of wheat chips during frying
Yuksel, F.; Karaman, S.; Kayacier, A.
In the present study, wheat chips enriched with barley flour at different concentrations (5, 10, 15, 20, 25 and 30%) were produced and some physicochemical and textural properties, fatty acid composition and sensory quality of enriched chips were investigated. An increase in the values of some physicochemical parameters of wheat chips, namely hardness, dry matter, ash and some fatty acids levels, was observed with the increasing barley flour concentration in the formulation. Barley flour addition provided a significant oil uptake reduction as the oil content of the control sample was 27.23% while that of the enriched samples with 30% barley flour was 18.21%. Overall acceptability of wheat chips added with no barley flour samples was determined to be similar to compared to enriched ones. But addition of barley flour higher than 10% caused a decrease in sensory scores of the final products.
AtıfScopus16WoS11OpenAlex11İncele - MakaleAçık Erişim2010Scopus SJRQ1Relative contributions of crust and mantle to generation of Campanian high-K calc-alkaline I-type granitoids in a subduction setting, with special reference to the Harşit Pluton, Eastern Turkey
Karsli, Orhan; Dokuz, Abdurrahman; Uysal, Ibrahim; Aydin, Faruk; Chen, Bin; Kandemir, Raif; Wijbrans, Jan
We present elemental and Sr-Nd-Pb isotopic data for the magmatic suite (~79 Ma) of the Harşit pluton, from the Eastern Pontides (NE Turkey), with the aim of determining its magma source and geodynamic evolution. The pluton comprises granite, granodiorite, tonalite and minor diorite (SiO2 = 59.43-76.95 wt%), with only minor gabbroic diorite mafic microgranular enclaves in composition (SiO2 = 54.95-56.32 wt%), and exhibits low Mg# (<46). All samples show a high-K calc-alkaline differentiation trend and I-type features. The chondrite-normalized REE patterns are fractionated [(La/Yb)n = 2.40-12.44] and display weak Eu anomalies (Eu/Eu* = 0.30-0.76). The rocks are characterized by enrichment of LILE and depletion of HFSE. The Harşit host rocks have weak concave-upward REE patterns, suggesting that amphibole and garnet played a significant role in their generation during magma segregation. The host rocks and their enclaves are isotopically indistinguishable. Sr-Nd isotopic data for all of the samples display ISr = 0.70676-0.70708, εNd(79 Ma) = -4.4 to -3.3, with TDM = 1.09-1.36 Ga. The lead isotopic ratios are (206Pb/204Pb) = 18.79-18.87, (207Pb/204Pb) = 15.59-15.61 and (208Pb/204Pb) = 38.71-38.83. These geochemical data rule out pure crustal-derived magma genesis in a post-collision extensional stage and suggest mixed-origin magma generation in a subduction setting. The melting that generated these high-K granitoidic rocks may have resulted from the upper Cretaceous subduction of the Izmir-Ankara-Erzincan oceanic slab beneath the Eurasian block in the region. The back-arc extensional events would have caused melting of the enriched subcontinental lithospheric mantle and formed mafic magma. The underplating of the lower crust by mafic magmas would have played a significant role in the generation of high-K magma. Thus, a thermal anomaly induced by underplated basic magma into a hot crust would have caused partial melting in the lower part of the crust. In this scenario, the lithospheric mantle-derived basaltic melt first mixed with granitic magma of crustal origin at depth. Then, the melts, which subsequently underwent a fractional crystallization and crustal assimilation processes, could ascend to shallower crustal levels to generate a variety of rock types ranging from diorite to granite. Sr-Nd isotope modeling shows that the generation of these magmas involved ~65-75% of the lower crustal-derived melt and ~25-35% of subcontinental lithospheric mantle. Further, geochemical data and the Ar-Ar plateau age on hornblende, combined with regional studies, imply that the Harşit pluton formed in a subduction setting and that the back-arc extensional period started by least ~79 Ma in the Eastern Pontides.
AtıfScopus167WoS163OpenAlex162İncele - MakaleYalnız künye2011Scopus SJRQ1Operating regimes of the government: Accounting and accountability changes in the sultan süleyman waqf of the ottoman empire (the 1826 experience)
Yayla, Hilmi Erdoǧan
Following Foucauldian accounting research, this article analyzes the relationship between accounting changes and "governmentality" practices by examining the accounting and accountability changes in the Sultan Süleyman Waqf of the Ottoman Empire in accordance with the restructuring regulations of Evkaf-i{dotless} Humayun Nezareti, established in 1826 for the purpose of the centralization of waqfs. It is argued that accounting was a technique in the hands of the Ottoman government that facilitated the translation of imperial objectives of the 1826 regulation into practice, the formation of the waqf in tune with government's desired outcomes, and the construction of governable bodies, as well as providing a controlling device from a distance (Latour, 1987; Miller & Rose, 1990). This article also aims to show how accounting and accountability techniques were used to make people calculable in the organizational spaces of an Islamic state standing in history (Foucault, 1991a). Thus, this article adds to the Foucauldian understanding of the role and functioning of accounting by examining a non-western oriented setting.
AtıfScopus56WoS52OpenAlex69İncele - MakaleYalnız künye2014Scopus SJRQ3Are output fluctuations transitory in the MENA region?; [Jesu li fluktuacije proizvodnje tranzitorne u mena regiji?]
Doǧru, Bülent
This study analyzes the nonstationarity of per capita real GDP for 11 Middle East and North Africa (MENA) Countries over the period 1970 to 2012 using two recently developed methods. SURADF and CADF panel unit root tests allowing for cross sectional dependence are used to determine whether output fluctuations are permanent or transitory. Contrary to the traditional view of business cycle, we Find econometric evidence supporting the idea that the output fluctuations in MENA region are mostly permanent. These results also emphasize that the effectiveness of stabilization policies aimed at real output by the government should be reviewed to achieve long-lasting results.
- MakaleYalnız künye2013Scopus SJRQ1The effects of antifreeze use on physical and mechanical properties of concrete produced in cold weather
Çullu, Mustafa; Arslan, Metin
This study examined the effects of antifreeze on the physical and mechanical properties of the concrete which are produced in cold weather. 30% Calcium Nitrate and 5% hydroxyethylaminemixture (HEA), Calcium Nitrate (KN) and Polyhydroxy Amine (PA) were used as additives in antifreeze. Prepared concrete samples were placed in a formwork and exposed to the frost at 0 °C, -5°C, -10°C, -15°C and -20°C for 2 days. Afterwards, concrete samples in the freezer were cured at the room temperature until the 28th day and permeable pore space volume, water absorption ratio, density, capillarity ratio, impermeability, compressive strength, static modulus of elasticity, Poisson's ratio and tensile strength values of the concrete samples were determined after the curing. In conclusion, 30% Calcium Nitrate and 5% hydroxyethylaminemixture (HEA) were found to be giving the best performance among the antifreeze types. The physical and mechanical properties of the concrete were negatively affected from all antifreeze types due to the temperature decrease of the exposed fresh concrete.
AtıfScopus47WoS37OpenAlex44İncele
