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Öğe Assessment of Bohme surface abrasion resistance of natural stones by simple and nonlinear multiple regression methods(Elsevier Sci Ltd, 2024) Teymen, AhmetNatural stones are widely used in the construction sector and the physico-mechanical features are very important for them in terms of areas of use. Abrasion is an important phenomenon for causes to decrease in aesthetical and mechanical properties. The Bohme surface abrasion (BSA) test is the widely used test method to determine abrasion resistance, but it is time-consuming, very difficult, and expensive to apply. Because of such difficulties, this study has been conducted to indirectly determine the BSA value of natural stones by some practical methods. For this purpose, BSA, Point load index (Is50), Shore Schlerescope hardness (SSH), Brinell hardness (HB), Rock impact hardness number (RIHN), Coefficient of rock strength (CRS), Crushability index (CI), Impact strength index (ISI), Water absorption (WA), Unit weight (UW), and Porosity (Pg) properties of a total of up 119 rocks, mainly of Turkish rocks, were determined. The main objective of this article is to develop some estimation models for the BSA of different rocks. Two different methods have been utilized in the modeling of data, including simple regression analysis (SRA), and nonlinear multiple regression analysis (NMRA). In addition to the SRA performed using all data sets, the SRA analysis was deepened by classification according to origin, porosity, and strength. A large number of estimation equations were obtained by NMRA performed by applying three different models. The actual BSA values obtained from the laboratory study and the BSA values obtained from the models analyzed with SPSS software were compared using ANOVA analysis and various graphics. The most successful SRA equations derived using the entire dataset were obtained with HB, Is50, and SSH parameters, respectively. In general, there is a significant correlation between various rock properties and BSA, except CRS and CI. For NMRA models constructed with at least three independent variables, the highest predictive power belongs to the equations using (Is50 / HB / UW), (Is50 / HB / CRS), and (Is50 / UW / WA / Pg) parameters, respectively. Rock abrasion has a complex nature. The results of this study strongly support that it is an accurate approach to seek a solution to this complex problem by using parameters such as hardness, strength, and physical properties in the same model.Öğe Betonun Elastisite Modülünün Agrega/Kayaç Özelliklerinden Tahmini(2018) Teymen, AhmetBu çalışma, agrega malzemelerinin sağlam kayaçlarının fizikomekanik özelliklerinin betonun mukavemet performansı (elastisite) üzerindeki etkisini incelemektedir. Bu amaçla çeneli kırıcı kullanılarak dokuz farklı agrega üretilmiş ve bu agregalar dokuz farklı betonun üretiminde kullanılmıştır. Betonların yapımı sırasında, su-bağlayıcı oranları, çökme ve işlenebilirlik temelinde, 0,28 ile 0,55 arasında tutulmuştur. Agrega ve kayaç özelliklerini belirlemek için toplam on yedi test yapıldı. Betonların elastisite modüllerini (Ec) tahmin etmek için basit ve çoklu doğrusal regresyon analizleri (SPSS) gerçekleştirilmiş ve denklemlerin doğruluğu F ve t-testi ile test edilmiştir. 28 günlük kür süresine göre, ilgili agrega kayaçlarının fizikomekanik özellikleri ile Ec arasında güçlü korelasyonlar elde edilmiştir. Bu çalışmanın sonuçlarından %72,2-%98,2 aralığında değişen yüksek korelasyon katsayılı basit denklemler elde edildiğinden, Ec parametresi ile kayaçların mühendislik özellikleri arasında iyi ve güvenilir ilişkiler olduğu belirlenmiştir. Ayrıca, çoklu regresyon modelleri, basit modellerden daha iyi bir tahmin verimliliğine sahiptir ve Ec’yi yeterli bir güvenirlikle tahmin etmek için uygulanabilirler.Öğe CaCO3 İÇEREN KAYAÇLARIN SONDAJ İLERLEME HIZININ KAYAÇ ÖZELLİKLERİNDEN TAHMİN EDİLMESİ(2019) Teymen, AhmetDelinebilirlik, matkap ucunun formasyon veya kaya içerisindeki ilerleme hızı olarak tarif edilir. Madenciliğintüm aşamalarında, baraj, yol yapımı, tünel ve kanalizasyon gibi mühendislik çalışmalarında patlatma deliklerininolabildiğince ekonomik ve kısa zamanda delinebilmesi işletme maliyeti açısından oldukça önemlidir. Ekonomikve hızlı sondaj, kayacın mineralojisi, mekanik özellikleri ve kullanılan matkap tipi ile doğrudan ilişkilidir. Kayaçözellikleri, dünyanın her yerinde standart olarak uygulanabilir olduklarından delinebilirlik ölçütü olarakkullanılmaktadır. Bu makale, CaCO3 esaslı kayaçlarda sondaj ilerleme hızının çeşitli kaya ve agrega testleri iletahmin edilmesi için gerçekleştirilmiş deneysel bir çalışmanın sonuçlarını içermektedir. Çalışmanın amacı,delinebilirliğe etki eden kayaç parametreleri ile laboratuvar karotlu sondaj çalışmalarından elde edilen verilerarasında regresyon analizi ile delme hızı tahmin modellerinin geliştirilmesidir. Yapılan basit ve çoklu regresyonmodelleri ile sondaj ilerleme hızının tahmininde yüksek korelasyon değerlerine sahip eşitlikler elde edilmiştir.Öğe Comparative evaluation of different statistical tools for the prediction of uniaxial compressive strength of rocks(Elsevier, 2020) Teymen, Ahmet; Menguc, Engin CemalIn this study, uniaxial compressive strength (UCS), unit weight (UW), Brazilian tensile strength (BTS), Schmidt hardness (SHH), Shore hardness (SSH), point load index (Is(50)) and P-wave velocity (V-p) properties were determined. To predict the UCS, simple regression (SRA), multiple regression (MRA), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and genetic expression programming (GEP) have been utilized. The obtained UCS values were compared with the actual UCS values with the help of various graphs. Datasets were modeled using different methods and compared with each other. In the study where the performance indice PIat was used to determine the best performing method, MRA method is the most successful method with a small difference. It is concluded that the mean PIat equal to 2.46 for testing dataset suggests the superiority of the MRA, while these values are 2.44, 2.33, and 2.22 for GEP, ANFIS, and ANN techniques, respectively. The results pointed out that the MRA can be used for predicting UCS of rocks with higher capacity in comparison with others. According to the performance index assessment, the weakest model among the nine model is P7, while the most successful models are P2, P9, and P8, respectively. (C) 2020 Published by Elsevier B.V. on behalf of China University of Mining & Technology.Öğe Effect of mineral admixture types on the grout strength of fully-grouted rockbolts(Elsevier Sci Ltd, 2017) Teymen, AhmetThis paper represent the results of an experimental study handled with developed grouting materials for fully-cement-grouted ribbed rockbolts. These experimental studies cover the effects of some mineral admixtures (silica fume, blast furnace slag, fly ash etc.) on the bond characteristics between grout and rockbolts. The effect of mineral admixtures on the grout strength of fully-grouted rockbolts and block punch index (BPI) and compressive strength (CS) of the grout on the load bearing capacity (LBC) were investigated. Totally 150 rockbolt pull-out tests were performed using ten different grouts in order to investigate and improve the LBC of grouted rockbolts for five different curing times (1, 3, 7, 28 and 90 days). All grout types were prepared same ratios, and silica sand was used as fine aggregate. Grout mixtures that 15% of mineral admixtures replaced with cement by weight were prepared. The results showed that grouts produced with silica fume (SF) and metakaolin (MK) in all mixtures were yielded the highest CS and bond strength at all ages. The all strength tests of fly ash (FA) grout exhibited low values till 28 days of curing time in accordance with reference grout, but a sharp increase was observed after this period. Grouts with perlite (PRL) and blast furnace slag (BFS) showed the similar strength values according to reference grout. In conclusion, mineral admixtures can be used for high-strength and low cost grout in tunneling applications. In addition, the use of waste materials can contribute to the resolution of environmental problems. (C) 2017 Elsevier Ltd. All rights reserved.Öğe ESTIMATING THE HARDNESS AND ABRASION PROPERTIES OF IGNEOUS ROCKS FROM CERCHAR INDENTATION DEPTH (CID)(Konya Teknik Univ, 2024) Teymen, AhmetThe most known and applied method for determining the abrasivity of rocks is the Cerchar Abrasivity Index (CAI). Properties of rocks such as abrasive mineral content, density, strength, and degree of cementation are the main factors affecting abrasivity, and these parameters likewise control their hardness properties. In this study, the average scratch depth formed on the rock surface after the CAI test was determined and it was investigated whether this calculated new parameter had the properties to represent the rock. Measurements were taken from four points along the scratch line formed on the surface with the help of a comparator and the average value was defined as the Cerchar Indentation Depth (CID). Measurements have shown that igneous rocks have CID values in the range of 0.01 mm-0.68 mm. Apart from the CID parameter, nine different properties (hardness, abrasivity, and physical) of fifty igneous rocks were tested. Statistically significant results were obtained by establishing relationships between CID and other rock mechanics tests. In CAI tests, it has been shown that CID measurements can be determined very sensitively if well-leveled core samples with parallel lower and upper surfaces are used. It has been determined that the CID value is directly related to the investigated rock properties and can be used as very useful experimental data in estimation studies.Öğe Estimation of uniaxial compressive strength of very low-medium abrasive rocks from Cerchar abrasiveness index(Pamukkale Univ, 2020) Teymen, AhmetCerchar Abrasiveness Index (CAI) is one of the commonly used methods for determining rock abrasiveness. The main parameters that affect abrasion are density, cementation, strength properties and amount of abrasive minerals in the rock etc. In this study, 15 different tests including uniaxial compressive strength (UCS) and CAI were performed on 35 different rocks with low-medium abrasive properties. UCS and CAI values of 35 rocks used in the study are ranged between 6.64 to 148.36 MPa and 0.68 to 2.67 respectively. All of the rocks are classified below the medium abrasiveness class according to CAI classification. The main purpose of the study is to estimate the UCS value which is known as the most commonly used rock feature by CAI values. For this purpose, it was tried to estimate UCS values by multiple regression method using CAI and other test parameters. The results of the study show that there are significant relationships between UCS and CAI.Öğe Maden galerilerinde farklı kaya kütle sınıflama sistemleri ile durabilite analizi uygulaması: Yahyalı/Kayseri Pb-Zn ocağı örneği(2024) Teymen, AhmetBu çalışma Yahyalı/Kayseri bölgesinde kurulu bulunan bir yer altı Kurşun-Çinko (Pb-Zn) ocağının ana nakliyat galerisinde gerçekleştirilen Kaya Kütlesi Karakterizasyonu ile ilgili saha ve laboratuvar çalışmalarını kapsamaktadır. Kaya malzemesi ve kaya kütlesi üzerinde yapılan detaylı çalışmalarla Kaya Kütle Puanlaması (RMR), Kaya Kütle Kalitesi (Q) ve Jeolojik Dayanım İndeksi (GSI) sistemleri ilgili tüm parametreler hesaplanarak duraylılık analizi yapılmıştır. Sonuçlar kireçtaşı formasyonu içerisinde açılan ana galerinin mevcut kesiti dikkate alındığında gerek duyulan bölümlerde lokal tahkimat uygulaması yapılması koşuluyla genel olarak tahkimatsız uzun yıllar ayakta kalabileceğini göstermiştir. Ancak madenlerin dinamik yapılar olduğu ve üretimle birlikte sürekli değişim geçirdikleri unutulmamalıdır. Kaya kütle koşulları, denetimsiz patlatma gibi mühendislik hataları ile değişebilecektir. Kullanılan kaya kütle sınıflama sistemleri ile her ne kadar bu sonuca varılmış olsa da, ani kaya kütle kalitesi değişimlerinin olabileceği lokasyonlarda (özellikle cevher zonları, fay zonu, erime boşluğu) ve tehlike arz eden yerlerde tahkimat uygulamasına mutlaka devam edilmelidir ve sürekli olarak denetlenmelidir.Öğe Statistical investigation of the effects of different origin aggregate properties on the mechanical properties of concrete(Pontificia Univ Catolica Chile, Escuela Construccion Civil, 2023) Teymen, AhmetAggregates are one of the most important components of the concrete mix and the aggregate properties have a great influence on the properties of the hardened concrete. From this point of view, the contribution of the nature of the aggregate to the general mechanical behavior of concrete should be better understood and investigated. The main purpose of this study is to present practical and useful equations for the rapid evaluation of the basic properties of concrete, especially during the preliminary design phase. A series of laboratory studies were conducted to determine the effects of twenty aggregates with very different origins and properties on various properties of concretes. Laboratory tests with the same or similar principles as aggregate rocks have been repeated for concrete samples produced using these aggregates.Nine SRA equations were generated to directly predict similar concrete properties with the help of aggregate properties. Equations with very high coefficients of determination were produced between various aggregate properties and concrete properties except for the SHH property. In addition, nonlinear multiple regression analysis (NMRA) was used for twenty-four equations to predict some basic properties of concrete (strength, abrasion, tensile, and impact). The performances of the derived equations were evaluated with a statistical tool developed by the author. Accordingly, the models with the strongest prediction capacity were obtained for STSC, LAC, CSC, and, IEC respectively. Results from NMRA showed that equations with the highest coefficient of determination were obtained with Model-3 for CSC (Equation 15), and STSC (Equation 18), and Model-1 for LAC (Equation 22), and IEC (Equation 31).Concrete has a complex structure that is affected by many parameters. In accordance with this complex nature, the approach to predict the main concrete properties with nonlinear multiple methods by including similar aggregate properties as well as non-destructive methods representing concrete/aggregate (hardness, ultrasonic pulse velocity and physical properties) has been successful. The extremely high coefficients of determination, ranging from 0.81 to 0.96, obtained with NMRA, indicate that basic concrete properties can be strongly predicted by aggregate properties and some concrete properties that can be tested non-destructively.Öğe Statistical models for estimating the uniaxial compressive strength and elastic modulus of rocks from different hardness test methods(Elsevier Sci Ltd, 2021) Teymen, AhmetIn engineering projects (dams, tunnels, slope stability) the strength characteristics of the rocks affect the construction operations. It is sometimes difficult, time-consuming, and expensive to evaluate the engineering properties of solid rocks by performing direct tests. For this reason, various laboratory studies have been carried out by many researchers to predict important engineering properties such as uniaxial compressive strength (UCS) and elastic modulus (E) of rocks in a practical way. One of the engineering properties used to estimate UCS-E practically is the hardness of rocks. Hardness tests are easy to apply and non-destructive, and in many of these tests very small specimens are needed. The main objective of this study is to analyze the relations between the UCS-E of the rocks and the various hardness methods (Schmidt hammer hardness, SHH; Shore Scleroscope hardness, SSH; Vickers hardness, HV; Brinell hardness, HB; and Indentation hardness index, IHI). For this purpose, the most appropriate and meaningful relations between hardness tests and UCS-E were determined by simple regression (SR) techniques. Relationships between main engineering properties (UCS, E) and physicomechanical properties were analyzed by multiple regression (MR) techniques using SPSS software. The statistical analyses made revealed the existence of strong correlations between UCS-E and hardness properties of rocks.Öğe The usability of Cerchar abrasivity index for the estimation of mechanical rock properties(Pergamon-Elsevier Science Ltd, 2020) Teymen, AhmetOne of the most commonly used methods of determining the rock abrasivity is Cerchar Abrasiveness Index (CAI). The basic parameters affecting abrasiveness are density, cementation degree, strength properties and the number of abrasive minerals in the rock. In this study, 20 different tests were carried out on 80 different rocks, mainly Young's modulus (E), uniaxial compressive strength (UCS) and CAI. The main aim of the study is to estimate the basic mechanical rock properties which are difficult to determine and time-consuming with the help of CAI values. In addition to simple equations, multiple regression equations were developed using CAI and other test methods (11 tests). Among the obtained equations, the most reliable ones were determined with the help of a developed performance index (PIat1). The results of the study show that there are significant relationships between basic mechanical rock properties and CAI.Öğe Yapı Taşı Olarak Kullanılan Tüflerin Eğilme Dayanımlarının Kaya-Agrega Özellikleri ile Modellenmesi(2019) Teymen, AhmetMerdiven basamaklarında, iç ve dış zemin döşemelerinde kullanılan doğal taşlar araç ve yaya yüklerinemaruz kalmaktadır. Yapı taşları genellikle farklı ölçülerde ebatlandırılmış plakalar şeklinde üretildiğindenbu malzemelerin eğilme dayanımı son derece önemli bir parametredir. Plakaların boyutu ve kalınlığı, desteknoktaları arasındaki mesafe, kayacın eğilme dayanımına göre tespit edilebilmektedir. Bu çalışmanın başlıcaamacı, yapı taşı olarak kullanılan tüflerin eğilme dayanımı ile uygulaması kolay ve düşük maliyetlimühendislik özellikleri arasındaki ilişkileri araştırmaktır. Bu çalışmada, 27 adet tüfün eğilme dayanımı(FTS), darbe dayanımı (DN), kayaç darbe sertlik numarası (RIHN), kaya dayanım katsayısı (CRS), darbedayanım indeksi (ISI), yassılık indeksi (FI), İsveç kırılganlık indeksi (S 20 ) ve porozite (P) değerleribelirlenmiştir. Tüflerin FTS değerinin tahmini için basit ve çoklu doğrusal regresyon analizleri (SPSS)gerçekleştirilmiş ve denklemlerin doğrulanması için F ve t-testleri kullanılarak denklemler doğrulanmıştır.Sonuçlar, kayaçların FTS ve mühendislik özellikleri arasında yeterli ve iyi ilişkiler olduğunugöstermektedir. Ayrıca, çoklu modeller, basit modellerden daha iyi tahmin verimliliğine sahiptir ve tüflerinFTS değerini yeterli güvenirlikle tahmin etmek için uygulanabilirler. Türetilen eşitlikler incelendiğinde,FTS’nin tahmini için kullanılan parametreler arasında S 20 , ISI, CRS, FI ve P gibi testler oldukça etkilidir.
