Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2021Scopus SJRQ3Aggressive environment performance of low energy cements containing fly ash
Gokce, H. Suleyman; Simsek, Osman
In this study, compressive strength performance of boron active belite cement containing fly ash at the ratios of 0, 10, 20, and 30% (by weight of cement) is researched against aggressive environments; sea water, 5% sodium sulphate solution, and 5% ammonium nitrate solution in addition to tapping water. Alternative low energy cement i.e., Portland-composite cement was used and its results were compared with those of boron active belite cement. Early strength losses (reaching up to 40%) of the boron active belite cement with incorporation of fly ash up to 30% were found to be less pronounced than those (reaching up to 51%) of Portland-composite cement in tapping water. Although, the losses were highly compensated with the prolonged curing period (90 days), boron active belite cement and Portland-composite cement kept their losses up to 14% and 36%, respectively. Residual mechanical properties (reaching up to 67%) of boron active belite cement against aggressive environments were found almost similar to those of Portland-composite cement in presence of 30% fly ash. In conclusion, the study shows that belite cements with low fly ash contents can be a reasonable alternative for specific applications such as mass concrete, hot weather concreting especially in aggressive environments.
AtıfScopus3WoS1OpenAlex5TR Dizin1
İncele - MakaleYalnız künye2012Scopus SJRQ1A nondestructive testing technique: Nail penetration test
Selcuk, Levent; Gökce, H. Suleyman; Kayabali, Kamil; Simsek, Osman
This study presents a practical nondestructive testing (NDT) method: the nail penetration test (NPT). The major tools of the test technique are a gas nailer with 130 J (95.88 ft-lbf) power, concrete nails, and a gas nailer cell. The study covers three different limestone aggregate types. Six concrete mixtures were prepared from each aggregate type. Five nail shots were performed on each concrete mixture (or grade) and the average value was obtained. The average nail penetration depths were correlated with the compressive strength of concrete. Other NDT techniques, such as the Schmidt rebound hammer (SRH), ultrasonic pulse velocity (UPV), and Windsor probe (WP), were also applied to concrete samples. The measured compressive strength values were compared with those obtained from the empirical relationships using the data from the NPT, SRH, UPV, and WP. It was found that the reliability of the NPT to estimate the compressive strength of concrete is very high. The tool employed in the investigation covers a relatively wide range of compressive strength of concrete. This testing tool is proposed to estimate the compressive strength of in-place concrete.
AtıfScopus15İncele - MakaleYalnız künye2011Investigation of Usability of Basaltic Pumice Aggregate At Prefabricated Structure Light-Weight Concrete Components
Gökce, H. Suleyman; Simsek, Osman
At prefabrication, concrete which is 30 MPa and more compressive strength is generally used in the production of structure components such as colon, beam etc. In new generation productions, expected property of the components is not only compressive strength, but also tensile splitting strength, bond strength and lightness which provides advantage on movement and molding. In this study, the engineering properties of the concrete prepared by CEM I 42.5 R type cement by using pumice and normal aggregate were investigated On determination of compressive strength 100x200 mm sized cylinder sample, on determination of tensile splitting and bond strength 150x150x150 mm sized cube sample and O12 ribbed steel bar was used. It is found that light-weight concrete (LC) which was prepared with pumice aggregate is 30% lighter than normal concrete (NC) prepared with normal aggregate and at equal strength. According to the NC, the LC was obtained by 48% less tensile splitting strength and 15% less bond strength.
- MakaleYalnız künye2010Ham perlit agregalı hafif beton özelliklerine alternatif genleştirilmiş perlit kullanımının etkisi
Simsek, Osman; Durmuş, Gökhan; Demir, İlhami; Gökçe, H. Süleyman
Perlit, ısı yalıtım ve hafiflik özelliğinden dolayı beton agregası olarak inşaat sektöründe kullanımı ile ülke ekonomisine ve küresel ısınmaya olumlu yönde katkıda bulunan doğal yapı malzemesidir. Yapılan araştırmalar sonucunda dünya perlit rezervinin yaklaşık % 74' ünün Türkiye'de olduğu belirlenmiştir. Bu doğal kaynakların etkin kullanımı ile oldukça zor elde edilen enerjinin daha etkin kullanımının sağlanacağı düşünülmektedir. Enerji kullanımındaki bu tür yaklaşımlar çevre kirliliğinin azalmasına katkı sağlayacaktır. Bu çalışmada, farklı özellikteki genleştirilmiş perlit agregalarının ham perlit agregalı hafif betonlar içinde kullanılabilirliği araştırılmıştır. Ham perlit agregası yerine hacimce %10 oranında üç farklı özellikte genleştirilmiş perlit agregası kullanılarak 7 ayrı karışım oluşturulmuştur. Hazırlanan hafif beton karışımları ile 100x100x100 mm ebatlı küp numuneler elde edilmiştir. Bu numunelerin 28 günlük basınç dayanımı, birim hacim ağırlık ve su emme oranları test edilmiştir. Sonuç olarak, uygun özellikteki genleştirilmiş perlit agregası kullanımının perlit agregalı hafif betonların mekanik ve fiziksel özellikleri üzerinde etkili olduğu anlaşılmıştır.
AtıfTR Dizin4İncele - MakaleYalnız künye2010Effect of Alternative Expanded Perlite Using on Properties of Raw Perlite Aggregated Light-Weight Concrete
Gökçe, H. Suleyman; Simsek, Osman; Durmus, Gokhan; Demir, Ilhami
Perlite is a natural building materials contribute to global warming positive thanks to its isolation and lightness characteristics as concrete aggregate with usage of in construction sector. In research results, about %74 of world perlite reserves was determined to be in Turkey. It is thought that energy of fairly hard obtained will provide more efficient usage thanks to efficient usage of the natural reserves. Such approaches will provide to reduce of environment pollution in the usage of energy. In this study, with different characteristic usability of expanded perlite aggregate was researched in raw perlite aggregated light weight concrete. 7 different mixtures were prepared in volume at 10% ratio by using 3 different expanded perlite aggregate instead of raw perlite aggregate. With prepared light weight concrete mixtures 100x100x100 mm sized cube samples were produced. 28 days compressive strength, unit volume weight and water absorption ratio of these sample were researched. As a result, with suitable characteristic usage of expanded perlite aggregate was understood to be effective on the mechanical and physical properties of perlite aggregated light weight concrete.
AtıfWoS3İncele - MakaleYalnız künye2010Scopus SJRQ2RESEARCH OF PESIMUM REACTIVE AGGREGATE RATIO OF THE PERLITE AGGREGATE WITH DIFFERENT METHODS
Gökçe, H. Suleyman; Simsek, Osman
In this study, it is purposed to determine of reactive aggregate ratio of the perlite aggregate for given up the highest length change. For this purpose, properties of relate to alkali-silica reaction (ASR) of the perlite aggregate determined with non-reactive limestone aggregate. For the determination of ASR, according to ASTM C 1260 accelerated mortar bar method, for microstructure; Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) analysis were carried out on the samples which are perlite, limestone and used both of them. Mixtures were prepared by weight at 0, 10, 20, 30, 40, 50 and 100% ratios with usage of perlite aggregate that obtained from Ankara Cubuk region instead of limestone aggregate that obtained from Ankara Hasanoglan region. 21 pieces of mortar bars were produced for 7 different mixtures. The length change values of the samples were measured on the 3, 7, 10, 14, 21 and 28-day according to the accelerated mortar bar method. Morphology and chemical composition of highest length changed samples were determined with SEM and EDX. Increase of fracture density and Ca ratio was observed in parallel with the increase of length change. According to average of 14 days length change, 40% perlite aggregated samples underwent highest length change and these samples were determined as pesimum reactive aggregate ratio of the perlite aggregate.
AtıfWoS3İncele - MakaleYalnız künye2010Scopus SJRQ2DETERMINATION OF ALKALI-SILICA REACTION EFFECTS OF ZEOLITIC TUFF ADDITION ON THE DIFFERENT AGGREGATES
Gökçe, H. Suleyman; Taban, Saniye; Simsek, Osman
The aim of this study is to determine the alkali-silica reaction (ASR) related characteristics of crushed stones that are produced from rocks of perlite, andesite and limestone when zeolitic tuff (ZT) is used in the mortar mix as cement replacement in different ratios. Accelerated mortar bar experiments in accordance with ASTM C 1260 were carried out on crushed stone aggregate samples to determine the ASR. CEM I 42.5 R type cement was replaced by ZT material in the following ratios: 0, 10, 20, 30 and 40%; in order to investigate the effects of replacement on the ASR pertaining to the aggregate types, 45 mortar bar pieces were produced. The length change values of the samples were measured on the 3, 7, 14, 28, 42, 56 days according to the accelerated mortar bar method. Measured length changes for the control samples on 14(th) day were found to be 0.570% at the level of potentially harmful for perlite, 0.101% at the level of critic for andesite and 0.061% at the level of harmless for limestone. Length changes at the harmful levels were taken under control for perlite at 30 and 40%, for andesite at 20, 30 and 40% ZT replacement ratios. Length change values of all samples decrease as ZT replacement increases. As a result, ZT replacement is effective to suppress the ASR of reactive aggregates.
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