LEE- Yapı Mühendisliği-Yüksek Lisans
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ÖgeFarklı çimento tiplerinde süper akışkanlaştırıcı ve rötre azaltıcı kimyasal katkıların performansının incelenmesi(Lisansüstü Eğitim Enstitüsü, 2023) Sapsızoğlu, Gökhan ; Akkaya, Yılmaz ; 781793 ; Yapı Mühendisliği Bilim DalıAlong with standard Portland Cement, many new cement types have become the reason for preference and need in the construction sector. In particular, the aesthetic and architectural expectations in the sector have increased the demand for white cement. In addition, mechanical and physical properties of white cement provide to the composite structure have increased the requirements for white cement in the production of construction chemicals. The demand for calcium aluminate cement has been increasing recently in our country as well as in many countries around the world. The main reason is that it is preferred due to its special phase structure like early high strength and fast setting time. The physical and mechanical properties of cement can be improved with the help of chemical additives in line with the expectations of the end user. Super plasticizer admixtures provide additional value for the mixture in terms of workability and ultimate strength. Shrinkage reducing admixtures contribute to the durability of the composite structure thanks to its shrinkage compensation feature. In this thesis, consistency, setting times, bending strengths, compressive strengths, shrinkage and vertical height change of different cement types produced in Turkey in two different phases were tested according to related standards. The chemical properties of cement types and chemical admixtures were tested according to TS EN 197-1 by the quality control team in advance and had been added in the beginning of chapter 3. Cem I 42.5 R Portland Cement, Cem I 52.5 R White Cement, Calcium Aluminate Cement and Ternary System Binder were used in the mixtures. Ternary systems are mainly created by mixing calcium aluminate cement, standard portland cement and gypsum. In addition to this mix, some other raw materials such as sands, mineral admixtures and specific chemicals are added in order to finalize the design. The rate of raw materials including cements are decided accorrding to expectations of projects. For instance, in cases where early strength is required, quantity of calcium aluminate cement in design would be higher. Also, gypsum is important in determining the setting time of designs. The study was first started with the cement paste stages. The mechanical and physical properties of these binders tested by adding shrinkage reducing admixture. In this phase, a constant flow 20±2 was aimed in all mixtures. Water reduction had been made in the mixtures, especially in cases where shrinkage reducing admixtures were added to ensure constant flow. The use of shrinkage reducing admixtures incrased the initial and final setting time in all binder types. Especially, these periods were almost doubled in white cement and ternary system. Although the use of shrinkage reducing admixtures increased flexural strengths, it decreased the ultimate compressive strengths. The second part was continued with the mortar. In this phase, the performance of 4 different cement types with shrinkage reducing admixture and super plasticizer admixtures were measured. Castings were started with mixtures without any admixtures, as reference mortars. Afterwards, the castings were continued by adding only shrinkage reducing admixture, only super plasticizer admixture, and both shrinkage reducing admixture and super plasticizer admixture at the same time. Since there is a super plasticizer as raw material input in the ternary system design, only castings with reference and shrinkage reducing admixture are made in this binder type. Again, at this stage, in order to examine the retardation in setting time of the calcium aluminate cement type, mortar castings were made with different kinds of super plasticizer based on polycarboxylate ether, and setting time and compressive strength were measured. Also in this phase, a constant flow 20±2 was aimed at all mixtures. Water reduction has been made in the mixtures, especially in cases where shrinkage reducing admixtures and super plasticizer admixtures were added to ensure constant flow. Target flow could not be achieved due to rapid hydration in ternary system mortars. The use of shrinkage reducing admixture in the mortar phase also slightly reduced the compressive strength. The use of super plasticizer admixtures provided high ultimate compressive strength in all binder types owing to its high range water reduction property. Super plasticizer admixture used in experiments caused the retardation of setting time in calcium aluminate cement; therefore, compressive strength could not be obtained at the 6th hour. Because of this situation, other super plasticizer admixtures which had got different raw materials were used in order to obtain 6th hour compressive strength. However, the sufficient early compressive strength value could not be reached in the 6th hour. Also, the use of other super plasticizer admixtures could not change the retardation of setting time. In the last part, shrinkage and vertical height change measurements were made in these 4 different binder types listed below: 1. Cem I Portland Cement 2. Cem I Portland Cement and superplasticizer 3. Cem I Portland Cement, superplasticizer and shrinkage reducing admixture 4. White Cement and superplasticizer 5. White Cement, superplasticizer and shrinkage reducing admixture 6. Calcium Aluminate Cement 7. Calcium Aluminate Cement and superplasticizer 8. Calcium Aluminate Cement, superplasticizer and shrinkage reducing admixture 9. Ternary System Binder (mix design has already superplasticizer) 10. Ternary System Binder (mix design has already superplasticizer) and shrinkage reducing admixture The use of shrinkage reducing admixtures in portland cement compensated for the shrinkage by almost 38% compared to the witness mortar. Vertical height changes were compensated by more than 50% thanks to shrinkage reducing admixture. In white cement, shrinkage reducing admixture could not show sufficient advantage in terms of reducing shrinkage. The use of shrinkage reducing admixture in calcium aluminate cement compensated for the shrinkage by more than 50% compared to the witness mortar. Vertical height changes were compensated by more than 60% thanks to shrinkage reducing admixture. In ternary system binder, shrinkage reducing admixtures enabled with decreasing the shrinkage by almost 50%. Super plasticizers caused the retardation of setting time in all designs. As a result of the experiments, it was observed that super plasticizer reduced water content and provided strength contribution in all cement types except the ternary system. As mentioned before, since the ternary system design has super plasticizer, no additional mixing which has super plasticizer was made. A It has been observed in experiments that shrinkage reducing admixtures significantly restrict the deformation in all cement types except white cement. The combination of white cement and shrinkage reducing admixtures should be reconsidered and retested.
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ÖgeModeling and sensitivity analysis the thermal behaviour of mass concrete with finite volume method(Graduate School, 2023-06-16) Danaei, Farzad ; Akkaya, Yılmaz ; 501201013 ; Structural EngineeringConcrete is one of the most widely used materials in the world, second only to water. As the population grows and available land becomes limited, there is a growing need for large structures such as dams and bridges and towers to meet the demands of water management, transportation, and accommodation. To ensure the strength and durability of these structures, high-performance concrete is often used. However, a major challenge in such concrete structures is thermal cracking, which occurs due to temperature gradients within the concrete. Concrete has low thermal conductivity, meaning that heat does not dissipate quickly throughout the material. As a result, the outer layer of concrete cools faster than the inner layer, creating thermal gradients. These temperature differences cause differential thermal expansion, if there is no restriction for these movements, there is no problem. But as soon as these movements are stopped by internal or external restrictions, the development of stress will start. When these stresses exceed the tensile strength of the concrete, cracks form. These cracks can result in issues such as water penetration, reduced structural integrity, durability problems (such as corrosion of embedded reinforcement), and aesthetic concerns. Different standards define limitations on the maximum temperature reached within concrete and the maximum temperature gradient within concrete elements, in Turkish standards (TS 13515 ) these limitations are 65 C and 25 C respectively. These specifications are designed to minimize the risk of thermal cracking by ensuring that concrete structures are maintained within safe temperature ranges throughout their service life. The finite volume modeling technique is used in the current model, which was developed in Python. The concrete element is separated into nodes in this manner, and for each node, a control volume according to its location is considered. Convection and conduction are taken into account as boundary conditions in the model, with the flexibility to include other heat transfer processes such as radiation and solar loads. Additionally, an equivalent convection coefficient is derived and employed in the model to account for the impact of formwork and insulation using the analogy of electrical resistance. The governing equation, which is developed from energy balance principles, is then applied to each node. This energy balance takes into consideration all of the energy that enters, is produced, is lost, and is stored inside the concrete. The present model is capable of accepting the ambient temperature using a predictive method, or it may also take actual temperature-time histories as input to improve its accuracy and dependability. The model incorporates the concept of maturity and calculates the heat generated during cement hydration using the Arrhenius maturity function. To simulate the heat generation, Schindler's S-shaped function is employed, requiring curve fitting techniques to determine two important hydration parameters: the slope parameter and time parameter. Unlike previous models that use a single set of hydration parameters, which fails to capture the behavior of blended cement, the current model addresses this limitation by utilizing the superposition of two S-shaped functions. This approach accurately catch all the points on the released heat curve for blended cement. By considering the behavior of blended cement, the model effectively captures the heat generation characteristics. From the S-shaped function, the generated heat rate function can be easily obtained. Additionaly, the model has the capability to accept the generated heat rate as an input. Accurately determining the generated heat rate function is crucial in simulating the thermal behavior of mass concrete, ensuring that the model accurately represents the actual heat generation process. During the experimental phase, data obtained from the Bursa Beton factory was employed. In Chapter 3 of the thesis, the experiment setup is described in detail, and the resulting outcomes are presented. This particular chapter focuses on investigating the impact of insulation on the temperature gradient within the concrete, as well as the influence of different concrete mixtures. The analysis of the collected data revealed noteworthy findings. When a thick layer of insulation was applied around the concrete, the temperature development recorded by the thermocouples placed inside the concrete exhibited similar behavior on both the right and left sides. However, in cases where no insulation was present and the concrete samples were exposed to the environment, distinct temperature profiles were observed between the right and left side sensors. This disparity in temperature can be attributed to the microclimate effect, which includes factors such as wind speed and solar loading on the concrete surface. It is worth noting that this effect has often been overlooked in previous models. The model has been developed in both 2-D and 3-D. The 3-D version is validated by simulating Bursa Beton samples and comparing the findings with experimental data, whereas the 2-D model is validated by comparing its results with the Ballims model. The 3-D model is additionally validated using data from a study carried out at West Virginia University. The model constantly exhibits sufficient accuracy in every validation instance, creating trust in its abilities and allowing sensitivity analysis to be carried out. Additionally, a sensitivity analysis is carried out to examine the impact of different variables on the temperature profile of mass concrete. The initial temperature of the concrete, the size of the concrete element, and the usage of supplemental cementitious materials (SCMs) in place of cement in blended cement are among the changes that have been taken into consideration. The results of the analysis show that the final temperature profile is significantly influenced by both the initial temperature and the size of the concrete part. However, the addition of SCMs to the concrete mixture lessens this sensitivity, especially when fly ash is used instead of some part of cement. Furthermore, when considering the utilization of different replacement levels of supplementary cementitious materials (SCMs), the findings demonstrate significant reductions in both the maximum temperature and maximum temperature gradient within the concrete. The results indicated that the usage of fly ash led to a greater reduction in the maximum temperature and temperature gradient compared to using GGBFS. Additionally, the presence of GGBFS resulted in a delay in the time required for the concrete to reach its maximum temperature. This suggests that adding fly ash to mass concrete lessens its sensitivity to changes in size while at the same time reducing the maximum temperature and thermal gradient inside the concrete. Furthermore, the degree of hydration affects the thermal properties of concrete, including its thermal conductivity and specific heat capacity. As the hydration reaction advances, the amount of available water or moisture inside the concrete drops, which causes a decrease in thermal conductivity and specific heat capacity. In earlier models, these thermal properties were frequently assumed to have constant values. A sensitivity analysis comparing the modeling results with constant thermal properties to those considering variations with hydration reveals that assuming constant specific heat capacity significantly impacts the final results. However, assuming a constant thermal conductivity does not cause substantial changes. In conclusion, the developed model offers a simple yet effective approach to predict the temperature distribution within concrete elements using the finite volume method. It accounts for various boundary conditions, considers the generation of heat during cement hydration, and incorporates the behavior of blended cement using a superposition of S-shaped functions. The model's accuracy is validated through comparisons with experimental data and existing models. Sensitivity analysis provides insights into the influence of different parameters and variations on the temperature profile. By addressing the thermal cracking issue, the model contributes to ensuring the safety, durability, and cost-effectiveness of concrete structures.
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ÖgePrediction of early-age mechanical properties of high strength concrete with pozzolans by using statistical methods(Graduate School, 2022-06-14) Dalgıç, Muzaffer Umur ; Akkaya, Yılmaz ; 501181029 ; Structure EngineeringThe developments in concrete technology are becoming more important and effective with the help of innovative approaches on materials and computer sciences and their applications. With advanced calculation methods, computing programs/softwares and supercomputers, the mechanical behavior of concrete is better understood in many aspects, today. In addition, the materials used in concrete technology are now much more diverse, more useful, and much more effective than in the past by the opportunities provided from the industry. On the other hand, this level of development and effectiveness still depends on specific needs of concrete. However, this natural limitation does not prevent performance improvement, durability, sustainability, environmental and budget-friendly expectations of concrete in a planned service life. Accordingly, while cement types, aggregates, moisture contents of aggregates, and air contents in concrete mixtures maintain their importance, the concrete mixture designs can be rearranged by weight and/or concrete mixing ratios according to the relevant pioneer test results, and new concrete matrices can be obtained by using fly ash, micro silica, nano silica, ground blast furnace slag, fiber, glass, wood, etc. Moreover, recyclable materials such as water, aggregate, glass, fiber, wood, etc. and even living organic materials are the topics that the concrete industry has recently focused on. In this context, the idea of using new construction materials may arise depending on relevant test results of special concretes produced for special projects. However, willing to change the concrete mixture designs and/or building materials based on test results can be quite difficult, because of time and budget concerns. For this reason, the most used type of concrete in the ready mixed concrete world is normal weight concrete (NWC), which is adapted by the concrete industry. Considering this fact, despite all the possibilities, determining a right concrete mixture design still differs in many ways depending on time, material, and external factors. In this idea, in general, specimens of hardened concrete in the form of cubes, cylinders, and rectangular prisms are tested at an early age to obtain results of mechanical properties such as compressive strength, splitting tensile strength, and modulus of elasticity so that further investigations and predictions of the concrete can be made. According to these test results, statistical methods come to the fore in many cases in terms of time and cost efficiency, and deep analysis to predict results of concrete performance depending on time and material to decide whether these concrete mixture designs comply with standards and regulations. Because, in regression analysis, which is one of these statistical methods, it is possible to predict a mechanical property of concrete without using destructive or non-destructive methods with enough concrete samples. In this way, the gains are obtained in terms of space, time, and cost. As a further step from the regression analysis, the use of machine learning methods such as Neural Net Fitting (NNF) to predict a data has become quite common today in the concrete world. Before statistical estimation of a data set, the concrete mixture designs should be cared for their validations. Furthermore, the atmospheric conditions at work sites where the concrete is casted are very important to obtain realistic test results from the concrete casting process. Therefore, the experiments such as slump, flow, unit weight, air content, ambient temperature, bleeding, adiabatic process, setting time etc. for fresh concrete samples can be carried out in the work fields. For this thesis, fresh concrete samples were taken for 33 different concrete mixture designs in 150X300 mm cylindrical sample containers in the numbers allowed by national standards and regulations. Besides, two distinct types of fine aggregates (FA) and three diverse types of coarse aggregates (CA) were used in these mixture designs with fly ash (FA) + micro silica (MS), ground granulated blast furnace slag (GGBS), and five different cement (C) types were used as binding material for these designs. The samples prepared within this framework were also kept in safe places in the worksites for the first setting process of the concrete, right after the sampling process was completed. Subsequently, the concrete samples, when the initial setting process were completed, were transferred to the laboratory environment for the hardened concrete tests in the international standards for 0.5, 1, 2, 3, 7, 14 and 28 days. And, the samples were prepared for the compressive strength, splitting tensile strength and modulus of elasticity tests for statistical analysis and estimations. In this thesis, as one of the statistical analysis models, regression analysis based on convergence of the obtained estimation results to real data (drawing curves) are used. The properties such as age of concrete samples (time), unit weights of mixture components, unit volumes of mixture components, mixing ratios and/or coefficients of an estimation methods etc. were analyzed individually and cumulatively. Accordingly, the relations of the predicted data with the concrete mixture designs are studied with linear or non-linear equations in univariate and multivariate regression models. In addition to the equations used for the estimation of the test results, other statistical results such as R (Correlation of Coefficient), R² (Coefficient of Determination), R²adj (Adjusted Correlation of Determination), Sum of Squared of Errors (SSE), Mean Square Error (MSE), and Root Mean Square Error (RMSE) were obtained. The relationships between the actual test results, and predicted results were examined at the end. Due to the nature of the models used in the univariate regression analysis, only one variable was considered, and the results were estimated accordingly. The number of variables taken into consideration was analyzed individually for each mixture design. Although such individual analyzes were possible, many sequential studies on the actual, and estimated results had been the cost of time. Therefore, predicting the actual results required more complex analyzes like the multivariate regression analysis in this study. Before the more complex analyses, the variables were studied one-by-one and/or in combinations for the multiple regression analyses. The substantial number of these combinations let the study to the machine learning process, and the effect of hidden layers between the input (mixture designs) values and the target (test) values four output values (algorithm results) were observed in the machine learning process. Although it was really complicated to detect these hidden layers by the individual calculations, only the input values, and target data values were chosen in the machine learning procedure without stepping directly into the hidden layers. On the other hand, it was understood that increasing the number of hidden layers deviated the estimation results from the target values. Therefore, to obtain more accurate results, the number of samples in the machine learning algorithms were changed as much as possible, while the number of hidden layers was increased. Yet, it was revealed that increasing the number of samples and/or hidden layers at the same time caused undesirable estimation results. It was also determined that an infinite number of experiments could be made with the machine learning to predict the target values. But, since it was not possible to conduct an infinite number of trials one-by-one, all trials were recorded first, and then evaluated from the best to the worst and/or in the Levenberg-Marquardt (LM) algorithm form the NNF machine learning process. In addition to this, R and MSE values in the NNF machine learning process, training, validation, test, and all correlation results were displayed in the x - y planes. Finally, in this framework, the best results were shared in association with the statistical results with physical meanings specific to mixture designs.
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ÖgeYüksek performanslı betonlarda erken yaş ısı gelişimi ve rötre(Lisansüstü Eğitim Enstitüsü, 2022-06-14) Duran, Özlem Ezgi ; Akkaya, Yılmaz ; 501181038 ; Yapı MühendisliğiYüksek performanslı beton, uzun servis ömrü istenen özel yapılarda mineral katkıların ilavesiyle düşük su/çimento oranının elde edildiği ve kimyasal katkılarla işlenebilirliği artırılan, dayanımı yüksek bir betondur. Üretim sırasındaki yüksek maliyetine rağmen ileride uzun servis ömrü sayesinde daha ekonomik sonuçlar elde edilmektedir. Tez çalışmasında yüksek performanslı betonların erken yaştaki ısı gelişimi ve erken yaş rötresi ele alınmıştır. Bu tür betonlarda erken yaş davranışının incelenmesi ve önceden tahmin edilebilmesi, ileri yaşlardaki dayanım ve dayanıklılığının öngörülebilmesi açısından önem taşımaktadır. Bu doğrultuda beton bileşenlerinin özelliklerinin erken yaş davranışına etkisi araştırılmıştır. Erken yaş rötre ve ısı gelişimi davranışının tahmin edilebilmesi için ek çalışmalar yapılmıştır. Rötre için genel bir fonksiyon denklemi bulmaya çalışılmıştır. Isı gelişimi için ise bir simülasyon çalışması yapılmıştır. Betonun erken yaştaki ısı gelişiminin çimento hidratasyonu ile ilgisi olduğu bilinmektedir. Bu nedenle ekzotermik bir reaksiyon olan hidratasyonun nasıl ve ne hızda gerçekleştiği, bu reaksiyonun nelerden etkilendiği ve ortaya çıkardığı ısı miktarı araştırılmıştır. Hidratasyon mekanizması incelendiğinde, bir miktar çimento kimyasına da giriş yapılmaktadır. Burada çimentonun klinker yapısını oluşturan ana bileşenlerin hidratasyonda önemli bir rol oynadığı görülmektedir. Çimentodaki (C2S, C3S, C2A, C4AF) karmaoksitlerin bulunma miktarlarına göre çimentonun beton davranışı üzerindeki etkisi çeşitlenmektedir. Yüksek miktarda C3S ve C3A içeren çimentolu betonlarda daha yüksek ısı çıkışı olacağı bilinmektedir. Betonda erken yaşta oluşan bu yüksek ısının erken yaş çatlağına sebep olacağı tahmin edilmektedir. Yüksek ısının açığa çıktığı durumlarda hidratasyon reaksiyonunu yavaşlatmak için puzolanik katkıların eklenmesi de bir seçenektir. Genel olarak puzolanik katkıların ilavesi çimentonun hidratasyonu yavaşlatmakta ve ısıyı düşürmektedir. Ayrıca çimentoda boşlukları doldurucu etkisiyle su/çimento oranını düşürmekte ve betonun kalitesini artırmaktadır. Bu yüzden puzolanik katkılar yüksek performanslı betonlarda sık kullanılmaktadır. Bunun yanında su/çimento oranının düşmesi hidratasyon reaksiyonlarını azaltacağı için ısıyı da düşürmektedir. Betonun ısı gelişiminde agrega varlığı da önemli bir etkendir. Beton içeriğindeki agreganın tane boyutunun artması ve agrega hacminin artması, çimento miktarını düşüreceği için su ihtiyacı da azalmaktadır. Bu da hidratasyon reaksiyonu oranını azaltarak betonda gelişen ısıyı düşürecektir. Bunun yanında agrega türüne göre değişkenlik gösteren su emmesi fazla agregaların iç yapıdaki mevcut suyu depolaması, çimentodan suyu uzaklaştırarak hidratasyonu azaltmaktadır. Genellikle priz süresi kısa olan betonlarda ise daha hızlı bir ısı gelişimi olduğu görülmektedir. Çalışmada araştırılan bir diğer ana konu ise erken yaş rötresi ve erken yaş rötre özelinde de otojen rötredir. Düşük su/çimentolu betonlarda hidratasyon reaksiyonu sırasında su tüketildiği düşünülürse betondaki suyun azalmasının rötreye sebep olacağı tartışılmazdır. Bu durumda erken yaşlardaki rötre davranışının sebebini yakından incelemek ve başka nelerden etkilendiğini öğrenmek önemli olmaktadır. Erken yaşta sıklıkla kuruma, termal ve otojen rötre gözlenmektedir. Erken yaşlardaki otojen rötre kendiliğinden kuruma ve kimyasal rötrenin de bir toplamıdır. Çalışmada otojen rötre üzerinde durulmasının sebebi literatürde düşük su/çimento oranına sahip yüksek performanslı betonlardaki yüksek otojen rötrenin beton kalitesinin düşmesi üzerinden oluşturduğu kaygıdır. Erken yaşta meydana gelen yüksek otojen rötrenin çatlaklara sebep olacağı ve çatlakların ilerlemesi ile ileri yaşlarda durabilite bakımından zayıf bir beton elde edileceği düşünülmektedir. Bu durum ise yüksek performanslı betonların durabilite bakımından geleneksel betonlara karşı daha verimli olma iddiasını olumsuz yönde etkileyecektir. Bu nedenle çalışmada otojen rötre davranışına nelerin sebep olduğu ve erken yaş rötrelerle birlikte otojen rötrenin nelerden etkilendiği konusu üzerinde durulmuştur. Erken yaşta ısı gelişimini artıran hususların otojen rötreyi de doğru orantılı olarak artırdığını düşünmek doğru bir yaklaşımdır. Toplamda sekiz deney betonu; s/b oranı 0.32-0.40 aralığında CEM I ve CEM III çimentolu, agrega tipi ve boyutu değişken malzemeleri içermektedir. Betonların taze haldeki özelliklerinin tespiti için taze beton deneyleri yapılmıştır. Taze beton deneylerinden çökme deneyi, yayılma tablası deneyi, birim ağırlık deneyi, hava içeriği deneyi ve priz süresinin tayini deneyleri uygulanmıştır. Deney betonlarının erken yaş ısı gelişimi için yarı adyabatik kalorimetre deneyi yapılmıştır. Erken yaş rötre için ise lvdt (doğrusal şekil değiştirme probu) yardımıyla ölçüm alınmıştır. Betonların otojen rötresinin tahmini için bir model üzerinde çalışılmıştır. Literatürde de yer alan bu modelin yaklaşımı değerlendirilmiştir. Isı verileri ise hidratasyon tahmini için kullanılan genel hidratasyon modeli ile optimize edilmiştir. Değerlendirme ve yorumlar bu optimizasyon üzerinden gerçekleşmiştir. Betonların ısı gelişimini deney yapmadan tahmin edebilmek için ise bir simülasyon modeliyle hidratasyon davranışı taklit edilmeye çalışılmıştır. Bunu sağlamak amacıyla bilim insanları için oluşturulmuş sanal bir laboratuvarda VCCTL yazılımı ile mevcut malzemelerin kullanılabildiği bir ortamda simülasyon hazırlanmıştır. Bu yazılımın içindeki mevcut verilerin deney betonlarına benzemesi için yakın malzemeler seçilmiştir. Sonucunda simülasyon ve deney betonları kıyaslanmıştır. Mevcut deney betonlarının ısı gelişimi, bir simülasyon modeliyle yaklaşık tahmin edilebilirliğinin değerlendirmesi yapılmıştır. Elde edilen sonuçlara göre; Deney betonlarının; çimento inceliği ve s/b oranı arttıkça hidratasyon ısısı ve ısı gelişim hızı artmaktadır. CEM III çimentolu betonların hidratasyonu ilk saatlerde daha hızlı ve yüksek ısılıdır. Maksimum agrega tane boyutu (Dmaks), agrega su emmesi arttıkça ve puzolanik katkıların eklenmesiyle hidratasyon ısısında düşüş gerçekleşmekte ve hidratasyon gecikmektedir. Çimento inceliği ve hidratasyon ısısı artarken ve maksimum agrega tane boyutu (Dmaks), s/b oranı ve agrega su emme oranı azalırken otojen rötre yükselmektedir. Genel çıkarımları sağlamayan istisnalar mevcuttur. Deney betonlarının davranışındaki farklılıklar için mikroyapının incelenmesine ihtiyaç vardır. Erken yaş rötreyi tahmin edebilmek için bir model üzerinde çalışıldığında rötre verilerine uygun bir yaklaşım yapılabilmiştir. Bu model ile su/çimento oranı,agrega/çimento oranı ve katkı miktarının etkisiyle otojen rötrenin artış veya azalışı tahmin edilebilmektedir. Isı gelişimini tahmin edebilmek için VCCTL yazılımında bir simülasyon ile deney betonlarının hidratasyonu taklit edilmeye çalışılmış olup ilk 48 saatte oldukça iyi yaklaşım sağlanmıştır. Ancak ileri yaşlarda simülasyonun iyi çalıştığı söylenememektedir.