Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Optimization and Mechanical Performance of Alkali-Activated Bottom Ash and Polypropylene Fiber in Deep Mixing Columns
Yilmaz, Fatih; Kamiloğlu, Hakan Alper; Avlayan, Büşra
Deep mixing columns (DMC) are one of the widely used soil improvement methods in cohesive and cohesionless soils. Cement and lime are predominantly used as conventional binders in DMC grout. Due to high CO2 emissions from conventional binders, the feasibility of using alkali-activated binders as DMC grout is being investigated. This study was conducted in three main stages. In the first stage, the proportions of bottom ash and activator (mixture of 10M NaOH and Na2SiO3) were optimized to achieve the highest UCS value using response surface methodology (RSM). In the second stage, the influence of polypropylene fiber content was examined in detail by incorporating varying amounts of fibers into the optimized binder-activator mixture to determine the optimal fiber content. Since DMC are fully buried, they are cured in the soil media. In this case, the soil temperature, which varies along the depth of the soil, also becomes the curing temperature of the DCM. Due to climate, soil condition and thermodynamic based parameters, curing temperature of the DMC varies throughout the soil depth. Therefore, in the third stage, the effect of curing temperature on the mechanical properties of the stabilized samples was evaluated under different temperatures. Results of the study revealed optimal UCS values with AAB content of 0.3-0.5 and activator content of 0.45-0.5. Polypropylene fiber reinforcement further improved strength, reaching an optimum at 1.50-1.75% content. Curing temperature played a significant role, with UCS and modulus of elasticity increasing up to 30 °C, indicating the importance of considering environmental factors in DMC design. These findings suggest that the optimized mixture has the potential to replace conventional cement-based binders in DMCs, offering a more sustainable solution with lower carbon emissions. Furthermore, the observed influence of curing temperature highlights the need to account for subsurface thermal variations when designing DMCs, as these factors significantly affect strength gain and long-term performance.
- MakaleYalnız künye2024Scopus SJRQ2Optimization, Characterization, and Carbon Footprint Analysis of Alkali Activated Waste Tuff and Fly Ash Mixtures for Deep Mixed Columns
Kamiloğlu, Hakan Alper; Yilmaz, Fatih
Deep soil mixing (DSM) applications are one of the widely known soil stabilization techniques which can be applied to a wide range of soil types. Cement and lime are the major materials used as binders for DSM applications. However, as conventional binders lead to emit a large amount of CO2 during production, eco-friendly binders suitable for DSM applications have become prominent. Alkali-activated materials are good alternatives to conventional binders. This study was intended to investigate the usability of zeolite rich tuff wastes as an alkali-activated binder in DSM columns. Within this scope, the waste tuff and C-type fly ash mixture were used as an alkali-activated binder, and 10 M NaOH solution was used as an activator. Response surface methodology (RSM) was employed in experimental design to determine optimum components to obtain maximum unconfined compression strength and investigate the interaction between stabilization agents. From the RSM analysis the optimum ratios of activator (X1), waste tuff (X2), and precursor (X3) were determined as; X1 = 0.251, X2 = 0.548, and X3 = 0.538 for maximum UCS. UCS, mineralogical and microstructural characterization (XRF, XRD, SEM, EDX, FTIR) was performed for the DSM samples prepared considering the optimized components. It was determined that the UCS values of the 3, 7, and 28-day cured samples stabilized by considering the optimum values gave UCS values approximately 3 to 5 times higher than the lower limit values recommended by FHWA. As a result of mineralogical and microstructural investigation, the reason for the strength increase in the samples can be attributed to the formation of geopolymeric gel between the soil particles by tuff waste and fly ash activated with alkaline activator. Carbon footprint analyses were performed for 1m3 DSM columns produced with alkali-activated binders and ordinary Portland cement (OPC). From the analyses it was seen that the carbon footprint of the DSM column produced using alkali activated binders is lower than that of the DSM column obtained with OPC. After the general evaluation of the study, it is seen that the hypothesis that waste tuff can be used as environmentally safe alkali-activated binders instead of traditional binders is supported.
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İncele - MakaleAçık Erişim2023Scopus SJRQ2Optimizing and investigating durability performance of sandy soils stabilized with alkali activated waste tuff-fly ash mixtures
Yilmaz, Fatih; Kuvat, Ahmet; Kamiloğlu, Hakan Alper
The search for alternative environmentally-friendly materials to Portland cement is increasing its importance in geotechnical engineering as in other fields. In this study, alkali activated waste volcanic tuff (BT) and fly ash (FA) utilized as an alternative to conventional binders. The specific objectives of this paper were to, (1) optimize fly ash, waste tuff and activator content using Response Surface Methodology (RSM), (2) investigate the UCS performance of the optimum amount of alkali-activated fly ash and waste tuff mixtures as a binder in soil stabilization by comparing with various codes, (3) characterize the optimized parameters, (4) examine durability performances of the samples. Optimum binder and activator content and effect of waste tuff on strength characteristics were evaluated statistically with RSM approach. XRF, XRD, FTIR analyses were performed to verify the synthesized alkali activated material in the inner structures of the optimized samples. The durability and mechanical properties of samples stabilized with alkali activated binders against soaking condition, wetting-drying and were investigated. Destructive and non-destructive methods were employed to examine mechanical and durability characteristics. Unconfined compression strength, strength reduction ratio, soil deterioration, and water absorption capacity was taken into account to evaluate durability performances. UCS values of the stabilized samples were compared with limit UCS values suggested by several standards. As a result of the study it was determined that alkali activated waste tuff and fly ash mixture shows significant mechanical and durability performance in soil stabilization, and capable to use as an alternative to conventional non-green binders.
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İncele - MakaleAçık Erişim2021Strength and Durability Performance of Clayey Soil Stabilized with Lime and Marble Powder
Yilmaz, Fatih; Demir, Ersin
This paper investigated the effect of freezing-thawing and wetting-drying cycles on the strength and durability of clay soil stabilized with lime and marble powder. The test samples were prepared by adding 5%, 10%, 15% and 20% of marble powder, without and with 6% lime to the soil which is a high plasticity clay (CH) according to the Unified Soil Classification System. Unconfined compressive strength tests were performed after 7 and 28 days of curing periods. The durability behavior of the samples was examined by applying freezing-thawing and wettingdrying cycles to the prepared samples. The results of this study show that the presence of marble powder in the soil mixture has an important role in the improvement of strength. An increase in the number of wetting-drying cycles does not decrease the volumetric stability of the samples stabilized with marble powder. The use of lime and marble powder together increased the strength values compared to the natural soil and the use of lime only. It was concluded that the co-use of lime and marble powder had a positive effect on the strength and durability behavior of high plasticity clayey soil.
AtıfTR Dizin1
İncele - MakaleAçık Erişim2020Uçucu Kül ve Mermer Tozu Katkılarının Zeminin Stabilizasyonuna ve DonmaÇözülmesine Etkisinin Araştırılmas
Yilmaz, Fatih
Zemin stabilizasyonunda farklı katkı maddelerinin davranışı, uzun yıllardan beri geoteknik mühendisliğinde araştırılan bir çalışma alanıdır. Bu çalışmada uçucu kül ve mermer tozu atıkları, katı atık yönetimi kapsamında zemin stabilizasyonu için kullanılmıştır. Çalışma kapsamında, düşük plastisiteli killi bir zemine %25 uçucu kül ve sırasıyla %0, %5, %10, %15, %20 oranlarında mermer tozu ilave edilmiştir. Hazırlanan karışımların indeks ve dayanım gibi geoteknik özellikleri irdelenmiştir. Ayrıca, katkı maddelerinin zeminin donma-çözülme çevrimi sonucundaki dayanım değerlerine etkisi incelenmiştir. Çalışma sonucunda, uçucu kül+mermer tozu karışımlarının sadece uçucu kül içeren karışımlara göre daha yüksek dayanım sağladığı sonucuna varılmıştır.
AtıfOpenAlex5TR Dizin4İncele - MakaleAçık Erişim2020Usability of Midyat Stone Wastes in Soil Stabilization
Yilmaz, Fatih; Duman, Vedat
Improving the geotechnical properties of weak soils is described as soil stabilization. In this study, industrial wastes of Midyat stone were used to carry out soil stabilization. Midyat stone wastes, which are evaluated in the improvement of a low plasticity clay soil, were mixed with natural soil at 5%, 10%, 15% and 20% additive percentages. In the light of the data obtained, the presence of a different binder was needed and lime was chosen as the primary binder. Index, strength and durability tests were carried out in mixtures containing 5%, 10%, 15% and 20% Midyat stone waste with and without lime. When the results of the experiments were examined, it was determined that the use of Midyat stone waste as an additive alone was ineffective on strength and durability values. In use with lime, 49% increase in strength has been determined compared to only lime sample. As a result of the study determined that the effect of Midyat stone wastes on freezing-thawing is very limited and more effective on wetting-drying, it was concluded that these wastes can be used for stabilization of low plasticity soils with lime.
AtıfOpenAlex1TR Dizin1İncele - MakaleYalnız künye2020Scopus SJRQ4Effect of fineness on lime stabilization of low plasticity clays
Yilmaz, Fatih; Kocabey, Sefa
In this study, stabilization with lime was investigated within the scope of surface soil stabilization. The main aim of the study is to examine the grindability of the lime and investigate the effect of grinded lime on the strength and durability behavior of stabilized soil. This paper is divided into two parts. The first part deals with the grindability of the lime. The second part analyses the results of geotechnical tests with grinded and ungrinded lime. Ungrinded lime, 90% of which is below 48 microns, was reduced to less than 20 microns. The test samples were prepared by adding 2%, 4%, 6%, 8% and 10% of grinded and ungrinded lime to a low plasticity clay according to the Unified Soil Classification System. Curing times for strength tests were determined as 1, 7, 14 and 28 days. The properties of the prepared mixtures were investigated by their geotechnical properties such as index, strength and durability. In the light of the data obtained from the experiments, it is concluded that the fineness of the lime has a direct positive effect on the strength and durability characteristics.
- MakaleYalnız künye2020DYNAMIC BEHAVIOUR OF HISTORICAL BAYBURT GRAND MOSQUE
Yurdakul, Muhammet; Yilmaz, Fatih; Artar, Musa
In this study, the locations of the damages that would occur when a historical building was exposed to different earthquakes were determined. The selected building is Bayburt Ulu Mosque located in the city center of Bayburt and it was built by the Anatolian Seljuk Sultan II. Gıyaseddin. This selected historical building is modelled according to the macro modelling technique in the SAP2000 program using the finite element method. Modules of elasticity, poisson's ratio and weight per unit of volume of Bayburt Stone which is used in the mosque are determined by the experiment. Also, the properties of the ground on which the building was built are determined. As earthquake records which recorded on similar grounds, components of DZC180 and DZC270 of 17 August 1999 Kocaeli earthquake, components BOL000 and BOL090 of 12 November 1999 Düzce earthquake and components of ERZE-EW and ERZE-NS of 13 March 1999 Erzincan earthquake are used. In the results of the dynamic analysis made, quantities and locations of the strains that can occur in the historic mosque are determined.
- MakaleYalnız künye2019Scopus SJRQ2Investigation on seismic isolation retrofit of a historical masonry structure
Artar, Musa; Çoban, Keziban; Yurdakul, Muhammet; Can, Ömer; Yilmaz, Fatih; Yildiz, Mehmet B.
In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.
AtıfScopus12WoS12OpenAlex6İncele - MakaleYalnız künye2018Scopus SJRQ2Influence of freeze-thaw on strength of clayey soil stabilized with lime and perlite
Yilmaz, Fatih; Fidan, Duygu
Stabilization of clayey soil has been studied from past to present by mixing different additives to the soil to increase its strength and durability. In recent years, there has been an increasing interest in stabilization of soils with natural pozzolans. Despite this, very few studies have investigated the impact of pozzolanic additives under freeze-thaw cycling. This paper presents the results of an experimental research study on the durability behavior of clayey soils treated with lime and perlite. For this purpose, soil was stabilized with 6% lime content by weight of dry soil (optimum lime ratio of the the soil), perlite was mixed with it in 0%, 5%, 10%, 20%, 25% and 30% proportions. Test specimens were compacted in the laboratory and cured for 7, 28 and 84 days, after which they were tested for unconfined compression tests. In addition to this, they were subjected to 12 closed system freeze-thaw cycles after curing for 28 days. The results show that the addition of perlite as a pozzolanic additive to lime stabilized soil improves the strength and durability. Unconfined compressive strength increases with increased perlite content. The findings indicate that using natural pozzolan which is cheaper than lime, has positive effect in strength and durability of soils and can result cost reduction of stabilization.
AtıfScopus27WoS25OpenAlex15İncele - MakaleYalnız künye2017Fineness Effect of Pozzolanic Additive on Strength in Soil Stabilization
Yilmaz, Fatih
Improvement of physical, chemical, mechanical and hydraulic properties of poor bearing soil is called soil stabilization. Within the scope of this study perlite, has inadequate cementing ability by oneself, was used as a pozzolanic additive in stabilization of clayey soil. Lime was chosen as a primary binder due to its high CaO content. Soil was mixed with 6% of lime (optimum lime ratio) and 0%, 5%, 10%, 15%, 20%, 25%, 30% of perlite. Pozzolanic additive perlite was evaluated in natural and finely granulated forms in stabilization study. Geotechnical properties such as index and strength features of mixtures and how this properties may change by fining perlite was considered in the scope of this study. After 84 days of curing period, the highest unconfined compressive strength was determined as 3196 kPa in the samples containing lime and 20% perlite. Samples in which fine perlite was used as an additive material, the highest unconfined compressive strength was reached 3408.9 kPa in samples containing lime and 15% fine perlite. As a result of this study, in which by fining of perlite lower perlite rate gives higher strength values, it was found that fineness of pozzolanic additive perlite has direct effect in strength values
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