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Öğe Bir mermer ocağındaki tehlike ve risklerin değerlendirilmesi(2024) Demir Şahin, Demet; Eker, HasanTürkiye'deki mermer ocaklarında potansiyel tehlike ve riskler çeşitli faktörler sonucu oluşur. Bunlar arasında iş güvenliği standartlarının ihlali, ekipman arızaları, jeolojik yapıdaki değişimler, işçi eğitim eksikliği ve çevresel etkiler gibi unsurlar yer almaktadır. Bununla birlikte; mermer ocakları gibi endüstriyel ortamlarda meydana gelen iş kazaları çeşitli nedenlere bağlı olabilir. Bunlar arasında düşmeler, ekipman arızaları, kaya düşmeleri, kimyasal maruziyetler ve yorgunluk gibi faktörler yer alabilir. L matris risk değerlendirme yöntemi, endüstrinin birçok alanında kullanılan bir yönetim aracıdır. Bu yöntem, riskin olasılığını ve etkisini bir matris üzerinde değerlendirerek risklerin önceliklendirilmesini sağlar. L matris risk değerlendirme yöntemi, bu faktörlerin her birinin olasılığını ve etkisini belirleyerek bir matris üzerinde görselleştirir. Olasılık ve etki değerleri, düşükten yükseğe doğru derecelendirilir ve bu değerler çarpılarak risk seviyesi hesaplanır. Bu yöntem, mermer ocaklarındaki tehlike ve riskleri tanımlamak, önceliklendirmek ve yönetmek için etkili bir araç olabilir. Ancak, tam ve kapsamlı bir değerlendirme için işletmelerin uzmanlarla işbirliği yapması ve yerel yönetmeliklere uygun olarak hareket etmeleri önemlidir. Bu çalışma, Türkiye’deki bir mermer ocağındaki tehlike ve riskleri L tipi risk değerlendirme yöntemi ile analiz etmiştir. Elde edilen sonuçlar, mermer ocağında sondaj ve açık ocak işletme alanlarında ağır iş makinelerinin devrilmesi, kaya düşmesi ve büyük parçaların kopması gibi tolere edilemeyen risklerin ölümcül sonuçlar doğurabileceğini göstermektedir. Açık ocak alanındaki diğer belirgin riskler arasında makine ekipman çarpması, parça düşmesi ve toz gibi unsurlar yer almaktadır. Ayrıca, hijyen konuları da açık ocak ve genel işletme alanlarında dikkate değer bir risk olarak değerlendirilmiştir. Öte yandan, arızalar ve trafik kazaları, tolere edilebilir ve hafif risk grubu içinde sınıflandırılmıştır. Bu değerlendirme, iş güvenliğini artırmak için gerekli önlemlerin alınmasına yönelik önemli bir temel oluşturmaktadır. Bu kapsamında Türkiye’de yer alan bir mermer ocağındaki tehlike ve riskler L tipi risk değerlendirme yöntemi kullanılarak tanımlanmış ve risk değerlendirilmesi gerçekleştirilmiştir. Potential hazards and risks in marble quarries in Türkiye occur as a result of various factors. These include violations of occupational safety standards, equipment failures, changes in geological structure, lack of worker training and environmental impacts. However; occupational accidents occurring in industrial environments such as marble quarries can be due to various reasons. These may include factors such as falls, equipment failures, rock falls, chemical exposures and fatigue. The L matrix risk assessment method is a management tool used in many areas of industry. This method enables prioritisation of risks by evaluating the probability and impact of the risk on a matrix. The L matrix risk assessment method determines the probability and impact of each of these factors and visualises them on a matrix. The probability and impact values are ranked from low to high and the risk level is calculated by multiplying these values. This method can be an effective tool for identifying, prioritising and managing hazards and risks in marble quarries. However, for a complete and comprehensive assessment, it is important that enterprises cooperate with experts and act in accordance with local regulations. This study analyzed the hazards and risks in a marble quarry in Türkiye with the L-type risk assessment method. The results obtained show that intolerable risks such as tipping over of heavy machinery, falling rocks and breaking off large pieces in marble quarry drilling and open pit mining areas can have fatal consequences. Other significant risks in the open pit area include elements such as machinery and equipment impact, falling parts and dust. In addition, hygiene issues were considered a significant risk in open pit and general operating areas. On the other hand, breakdowns and traffic accidents are classified in the tolerable and mild risk group. This evaluation forms an important basis for taking the necessary measures to increase occupational safety. In this context, hazards and risks in a marble quarry in Türkiye were identified and risk assessment was carried out using the L-type risk assessment method.Öğe Curing Stress Influences the Mechanical Characteristics of Cemented Paste Backfill and Its Damage Constitutive Model(Mdpi, 2022) Chen, Shunman; Xiang, Zhenggui; Eker, HasanAs mechanical characteristics are one of the most important indexes that represent the backfill effect of CPB, curing stress is less considered, thus, establishing a damage constitutive model under the effect of curing stress has great significance for the stability of CPB. Firstly, a multifield coupling curing experiment was developed, and a uniaxial pressure testing experiment was used to test the mechanical parameters. Then, the evolution rule of mechanical characteristics of CPB, considering the effect of curing stress, was analyzed. Secondly, combined with elastic mechanics and damage mechanics theory, a damage constitutive model of CPB was explored. Thirdly, based on the laboratory results, an established damage constitutive model was verified. The results indicate that uniaxial compressive strength (UCS) of the CPB was significantly improved because of increasing curing stress and was also influenced by curing age. It was also shown that there existed four stages for the stress-strain curve of the CPB specimens. Moreover, the stress-strain curves of the model and the experiment's results were the same. There were also good validity and rationality for the established two-stage damage constitutive model, which can provide a good reference for engineering applications of CPB.Öğe Effect of Reduced Fineness of Fly Ash Used on the Alkali-Silica Reaction (ASR) of Concrete(Springer Int Publ Ag, 2023) Eker, Hasan; Demir Sahin, Demet; Cullu, MustafaThis study aimed to determine the effect of fly ash added to concrete with high calcium content (C class) and different fineness on durability properties such as the alkali-silica reaction (ASR). By substituting ultra-fine fly ash for cement at specific proportions in concrete mixes and increasing the fly ash fineness, fly ash filled the spaces between cement grains or aggregates in concrete and accelerated the hydration process. Thus, the mechanism of ASR development was reduced. Class C Afsin Elbistan ash was used and was ground in a ball mill for 0, 10, 20, 30, and 45 min, and Blaine fineness values of 1555, 1632, 2347, 2589, and 2766 cm(2)/g were obtained, respectively. For each fly ash fineness, the effect of mixtures with 10%, 30%, and 50% replacement of cement on the ASR mechanism was observed during curing periods of 3, 7, 14, and 28 days compared to concrete without fly ash admixture. Furthermore, the effect of the increased fineness and substitution rate of fly ash with high calcium content in cement on the microstructure was revealed by microscopic mineralogical images. The prepared fine fly ash added to concrete mixes at different replacement ratios showed ASR reducing properties compared to the concrete mix without additions. The fly ash fineness and the substitution rate in the concrete had a reducing effect on the ASR, and this effect resulted in values lower than the reference concrete value.Öğe Effects of Ultrafine Fly Ash against Sulphate Reaction in Concrete Structures(Mdpi, 2024) Sahin, Demet Demir; Eker, HasanIn this study, Afsin Elbistan C-type fly ash (FA) was used, which protects against the sulphate reaction that damages concrete. The detrimental effects of post-reaction decrease with increasing fly ash fineness. The study used 10%, 30%, and 50% weight substitutes of cement. The fly ash was ground in a ball mill for 0, 10, 20, 30, 45, and 60 min, and Blaine fineness values of 1555, 1632, 2347, 2589, 2766, and 3433 cm2/g were obtained, respectively. The effect of the samples on the sulphate resistance was investigated by exposing the samples to 5% or 10% added sulphate solutions, and the compressive strength and ultrasonic pulse velocity of the concrete were tested. The compressive strength values obtained decreased with the increase in sulphate content, and the increase in the grinding time and the amount of substituted FA increased the compressive strength values. It was observed that weight loss increased with increasing sulphate content and decreased with the addition of FA with a high Blaine fineness. It was determined that as the Blaine fineness value increased, the sulphate content, FA substitution amount, and ultrasonic pulse speed decreased. This study was carried out to determine the effects of fly ash used at different fineness and replacement ratios on the performance and strength of concrete after exposure to external influences such as sulphate. The use of fly ash instead of cement will reduce the use of waste materials and natural resources and prevent environmental pollution. The cost of cement and concrete will be reduced.Öğe Influence of silica fume on mechanical property of cemented paste backfill(Elsevier Sci Ltd, 2022) Eker, Hasan; Bascetin, AtacThe cemented paste backfill (CPB) method, which is the most preferred method for tailings storage, is one of the most used methods for the disposal of mine tailings. However, the high rate of cement usage increases the costs. In this study, whether silica fume (SF), which is a pozzolanic material, can be used as a substitute instead of cement was investigated based on mechanical parameters or not. As a result of the experiments, it was determined that SF substituted for portland cement (PC) increased the strength of paste backfill mixtures prepared in a certain cement ratio. In addition, it was determined that SF substitution in CPB increased the durability of mixtures against sulphate attacks as it did in concrete. With the use of SF, savings of up to 20% were achieved in the amount and cost of cement used in CPB. Besides, using it without the pulverizing process required for pozzolanic materials used in other studies had a positive effect in terms of time and cost. Moreover, the use of SF in CPB mixtures resulted in less energy use and less greenhouse gas emissions, and a reduction of environmental pollution caused by SF tailings.Öğe The investigation of geochemical and geomechanical properties in surface paste disposal by pilot-scale tests(Taylor & Francis Ltd, 2022) Bascetin, Atac; Adiguzel, Deniz; Eker, Hasan; Tuylu, SerkanToday, seepage control in tailings dams has become an important problem due to the increased production in mining sites. Although very techniques have been developed to solve this problem, research in this field continues. The reason for this is that there is an ongoing search for a one hundred percent successful method to prevent seepage. In this study, the geochemical and geomechanical properties of paste material stored by the surface paste disposal (SPD) method were investigated by pilot field tests. To determine the effects of cement and pozzolanic materials on the geochemical and geomechanical properties of the paste, 2 different pilot-scale storage designs were observed for about 1 year, with no additives (reference) and binder added to some layers (cement and fly ash). Based on the data derived from the former laboratory investigations and with no additives and with a few layers of cement and fly ash, the two different designs were applied on a pilot scale near the existing tailings dam of a currently active mining enterprise. These designs were observed in inland conditions for about 1 year to determine the effects of seasonal changes on the material. The seepage analysis, surface crack densities, microstructural properties, consolidation, and cohesion values of these designs, which are directly exposed to atmospheric effects, were determined during the study period. According to the results obtained, the use of cement improved the volume compressibility coefficient of the material by approximately 25% compared to the reference design. However, the use of fly ash alongside cement improved the volume compressibility coefficient by about 75%. In conclusion, the use of cement made the material more resistant to external factors, and the usability of fly ash, which was used at a 50% replacement ratio with cement to bring down the cost, for long-time storage in the industry was demonstrated within the scope of the study.Öğe Investigation of the usability of industrial mining wastes in agriculture(Frontiers Media Sa, 2023) Eker, HasanIn this study, the usability of the mixtures consisting of lignite coal taken from Tekirdag region and marble and travertine wastes taken from the marble factory in Gumushane region in local bean (Kelkit) cultivation was researched. First, control samples were created using only humus soil without coal, marble, or travertine dust. Then, for each coal or coal waste, coal/coal waste-waste marble dust and coal/coal waste-travertine dust mixtures were formed. These mixtures were obtained by mixing 25%, 50%, 75%, and 100% by weight of coal and 25%, 50%, and 75% by weight of marble and travertine dust. Afterwards, local beans were planted in these mixtures and their development was followed under laboratory conditions. Additionally, temperature and humidity values were recorded at certain intervals, pH and heavy metal analysis measurements were made on the mixtures before and after bean planting, the height and leaf measurement of the beans grown and the number of beans grown in these beans were also followed, and chlorophyll analysis was performed on the bean plants grown in these mixtures. As a result, 50% Coal-3D + 50% Travertine mixture had the maximum length increase, that 25% Coal Waste (Powder)-K3 + 75% Marble mixture had the highest number of beans, and that 50% Coal Waste -AK + 50% Marble mixture had the maximum leaf formation. In these mixtures, maximum 12 beans were grown and maximum 93 leaves were formed. Also, the bean plant was grown in all mixtures. The chlorophyll contents were at least as much as the values of the beans grown only in soil. However, heavy metal values do not exceed the permissible limit values in soil.Öğe Madenlerde iş sağlığı ve güvenliği alanında baret denetimi için yeni bir tasarım(2024) Eker, Hasan; Özlük, Mehmet FatihTürkiye’de, iş kazalarının son yıllarda arttığı görülmektedir. Meydana gelen iş kazalarının % 0.3’ü ölümle sonuçlanmaktadır. Türkiye’de her gün yaklaşık 4.2 kişi iş kazası sonucu hayatını kaybetmektedir. Meydana gelen iş kazalarının yapılan çalışmaların ortalaması dikkate alındığında yaklaşık % 14.6’sı baş ve boyun yaralanması olarak karşımıza çıkmaktadır. Madencilik sektöründe yaşanan iş kazaları sonucu baş ve boyun yaralanmalarının sebepleri arasında çalışanların baretini takmaması, baret kullanmaması veya iş yeri içerisinde baretini çıkararak çalışması sayılabilir. Bu çalışmada; madenlerde çalışanların baretini çıkardığı anda, uzaktan algılanarak ve ilgili mühendis veya çalışanın ekranına çıkarıldığını haber veren bir baret tasarımı üzerinde durulmuştur. Tasarım olarak yapılan bu baret Karabük ilinde yer alan bir mermer işletmesinde tasarım aşamasında test edilmiştir. Sonuç olarak, madenlerde iş sağlığı ve güvenliği kurallarına uymayıp baret takmayan çalışanların iş kazasına yakalanmadan önce tespit edilerek baş ve boyun yaralanmaları gibi ciddi iş kazalarının önüne geçmesi amaçlanmaktadır. In Turkey, occupational accidents have increased in recent years. 0.3%of occupational accidents result in death. Approximately 4.2 people die every day in Turkey as a result of work accidents. Considering the average of the studies, approximately 14.6%of the occupational accidents are head and neck injuries. Among the reasons for head and neck injuries as a result of occupational accidents in the mining sector are not wearing a hard hat, not using a hard hat or working by removing the hard hat in the workplace. This study focuses on the design of a helmet that can be remotely detected and notified to the relevant engineer or employee's screen when the employee removes his/her helmet. As a result, it is aimed to prevent serious occupational accidents such as head and neck injuries by identifying employees who do not comply with occupational health and safety rules in mines and do not wear hard hats before they are caught in an occupational accident.Öğe The study of strength behaviour of zeolite in cemented paste backfill(Techno-Press, 2022) Eker, Hasan; Bascetin, AtacIn the present study, reference samples were prepared using ore preparation facility tailings taken from the copper mine (Kure, Kastamonu), Portland cement (PC) in certain proportions (3 wt%, 5 wt%, 7 wt%, 9wt% and 11 wt%), and water. Then natural zeolite taken from the Bigadic Region was mixed in certain proportions (10 wt%, 20 wt%, 30 wt% and 40 wt%) for each cement ratio, instead of the PC, to prepare zeolite-substituted CPB samples. Thus, the effect of using Zeolite instead of PC on CPB's strength was investigated. The obtained CPB samples were kept in the curing cabinet at a temperature of 25???C and at least 80% humidity, and they were subjected to the Uniaxial Compressive Strength (UCS) test at the end of the curing periods of 3, 7, 14, 28, 56, and 90 days. Except for the 3 wt% cement ratio, zeolite substitution was observed to increase the compressive strength in all mixtures. Also, the liquefaction risk limit for paste backfill was achieved for all mixtures, and the desired strength limit value (0.7 MPa) was achieved for all mixtures with 28 days of curing time and 7 wt%, 9 wt%, 11 wt% cement ratios and 5% cement ??? 10% zeolite substituted mixture. Moreover, the limit value (4 MPa) required for use as roof support was obtained only for mixtures with 11% cement ??? 10% and 20% zeolite content. Generally, zeolite substitution seems to be more effective in early strength (up to 28th day). It has been determined that the long-term strength losses of zeolite-substituted paste backfill mixtures were caused by the reaction of sulfate and hydration products to form secondary gypsum, ettringite, and iron sulfate.Öğe A study on precautions to be taken in the event of a pandemic in the mining industry in turkey(2023) Eker, HasanThe Covid-19 epidemic, a new species of coronavirus, has taken over the world. Like most industries around the world, the mining industry has a negative impact on this situation, such as stopping their business, loss of production, stopping new projects or postponing them, and their employees being infected by the epidemic. In this study, measures to be taken in the mining industry in Turkey have been attempted. In the study, the measures set out are to update the risk assessment according to the epidemic, identify the responsible people, arrange the work plan, set rules to be followed in vehicles, inform employees, organize training content, establish and apply hygiene rules, set rules to be observed in the workplace, limit interaction between employees and establish and apply rules related to common use. With the implementation of these rules, the Covid-19 outbreak is expected to reduce the impact on the mining industry in Turkey. The Covid-19 epidemic has no mining workers in Turkey who have been affected by this virus, but have died from this epidemic.Öğe Uçucu kül inceliğinin betonun sülfat direnci üzerine etkisi(2022) Şahin, Demet Demır; Eker, Hasan; Çullu, MustafaBeton bileşiminden biri olan çimentonun hidratasyonu ile sülfat iyonları arasında oluşan kimyasal reaksiyon sonucu sülfat korozyonu oluşmakta ve bu oluşum betonda bozulmalara neden olmaktadır. Sülfatın beton üzerinde oluşturduğu hasarı azaltmak ya da en aza indirmek için çimento yerine uçucu kül gibi puzolanlar kullanılmaktadır. Bu çalışmada betonun ana bileşenlerinden biri olan çimento yerine çimentoya yakın bileşene sahip olan Afşin Elbistan Termik Santralinden temin edilmiş uçucu kül atığı kullanılmıştır. Uçucu külün (UK) bilyalı değirmende 0, 10 ve 20 dk öğütülmesi ile elde edilen farklı inceliklere sahip örnekler % 10 UK ikame oranı ile hazırlanarak uçucu kül katkılı beton örnekleri oluşturulmuştur. Daha sonra bu örnekler; % 5 ve % 10 katkılı sülfat çözeltisine maruz bırakılmış ve beton örneklerinin sülfat direnci üzerine etkisini araştırmak için basınç dayanımı ve ultrasonik dalga hızı ölçümü testlerine tabi tutulmuş, ağırlık kayıpları incelenmiştir. Elde edilen sonuçlara göre uçucu kül öğütme süresine bağlı olarak % 5 ve % 10 sülfat çözeltisine maruz bırakılmıştır ve daha sonra katkılı beton örneklerindeki basınç dayanım değerlerinde artışlar gözlenmiştir. Sülfat çözeltisi miktarının artmasıyla birlikte beton örneklerinin basınç dayanımının azaldığı ve bu beton örneklerinin referans örneğine göre daha yüksek basınç dayanımı değerine sahip olduğu görülmüştür. Bununla birlikte; öğütme süresinin artmasıyla ağırlık kayıplarının azaldığı görülmüştür. Ayrıca; öğütmenin etkisi ile uçucu külün inceliğinin artması sonucu ultrasonik dalga hızı değerlerinin de arttığı belirlenmiştir.Öğe Utilization of tailings in concrete products: A review(Elsevier Sci Ltd, 2022) Adiguzel, Deniz; Tuylu, Serkan; Eker, HasanMany properties of concrete with tailings have been examined in the literature, but it is seen that there are not many studies on the environmental properties of these concretes. It is thought that the environmentally risky properties of these concretes limit the use of tailings. Due to the environmental risks of tailings, the concrete with these tailings also has the potential to cause environmental damage. For this reason, in addition to the me-chanical properties of the concrete with tailings, the environmental properties are also discussed as a separate topic, and the methods and studies used in this subject in the literature are presented in detail. Also, this study investigated the use of mining process tailings in concrete production instead of fine aggregate and cement. Thus, it was emphasized that evaluations should not only be made according to the mechanical properties of the concrete with tailings but also concrete's environmental characteristics should be taken into consideration. This study is designed to be used as a literature study for the use of different tailings instead of fine aggregate or cement in concrete and to determine tailings rates. In this context, the results of the mechanical and environ-mental (pH and heavy metals) studies of tailings with concrete products in the literature are given. The rela-tionship between the mechanical results in the study and the tailings rates was evaluated in terms of physical and chemical properties. As a result, the ratio of tailings to optimum use as fine aggregate was found to be substituted at between 10 and 40%. The amount of tailings substituted in cement, however, was estimated to be between 5 and 20%. In addition, in the studies, it was observed that the pH of metallic tailings varied between 5 and 8.3, while the heavy metal ions of the concrete containing the tailings were found below the drinking water and toxicological limits.
