Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2023Nanosilika Modifiyeli Bağlayıcıların Tekerlek İzi Direnci ve Sıcaklık Hassasiyetlerinin Belirlenmesi
Akpolat, Mustafa
Bu çalışmada, Nanosilika (NS) katkısının bitümlü bağlayıcıların tekerlek izi ve sıcaklık hassasiyetine olan etkisi değerlendirilmiştir. Bu kapsamda saf ve 3 farklı orandaki (%2, %4 ve %6) nanosilika modifiyeli bağlayıcılar üzerine penetrasyon, yumuşama noktası, viskozite ve çoklu gerilmeli sünme geri dönme (MSCR) deneyi uygulanmıştır. Saf ve NS modifiyeli bağlayıcıların sıcaklık hassasiyetini belirlemek için geleneksel deney sonuçlarından yararlanılarak penetrasyon indeksi (PI) ve penetrasyon-viskozite sayısı (PVN) belirlenmiştir. Elde edilen sonuçlara göre, saf bağlayıcının nanosilika ile modifiye edilmesiyle bağlayıcının kıvamında azalma ve viskozitesinde artış sağlanmıştır. Bu sayede sıcaklık hassasiyeti daha düşük modifiye bağlayıcılar elde edilmiştir. Ayrıca MSCR deney sonuçlarına göre nanosilika modifiyesinin bütün sıcaklıklarda daha düşük Jnr değerleri vererek bağlayıcının tekerlek izi parametresini geliştirdiği daha ağır taşıt trafiklerine cevap verebileceği ve yüksek servis sıcaklıklarında kullanılabileceği belirlenmiştir.
- MakaleAçık Erişim2023Determination of Rutting Resistance of SBS and Warm Asphalt Additive Binders by the MSCR Test
Akpolat, Mustafa
The MasterLife PAV110 Warm Mix Asphalt (WMA) additive’s rutting resistance in pure and Styrene-Butadiene-Styrene (SBS)-modified binders was examined using MSCR testing. Multiple Stress Creep Recovery (MSCR) tests were conducted on seven binders. The study’s findings indicated that the incorporation of WMA resulted in an increase in the Jnr values of both pure binders and binders modified with SBS at stress levels of 0.1 and 3.2 kPa. This finding implies that the occurrence of rutting will be negatively impacted. On the other hand, the performance level categorization showed that WMA additives had no impact on the performance levels of pure and SBS-modified binders. Since the Jnr and average percentage Recovery (R) values at 3.2 kPa, 1%, and 1.5% PAV110 additives exhibited similar properties, it was determined that the optimum usage rate in terms of cost was 1%.
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İncele - MakaleAçık Erişim2022Scopus SJRQ3Investigation of rutting, fatigue and cracking resistance parameters of CR modified warm asphalt binders compare with SBS modified binders
Akpolat, Mustafa
This study compares the rutting and cracking resistance and fatigue parameters of crumb rubber (CR) modified warm asphalt binders, which were determined by viscoelastic continuum damage (VECD) theory. The effect of the combination of CR modification and Sasobit, a warm mix additive, was investigated. Performance of CR + Sasobit compound was compared with styrene-butadiene-styrene (SBS) modification. Newly developed rheological tests such as multi stress creep recovery (MSCR), lineer amplitude sweep (LAS) and conventional tests were applied to modified binders. It was determined that the CR + Sasobit modified binders improved the rutting parameter better in comparison to SBS-added binders. Although the CR additive improved the rheological properties of the binder at low and medium temperatures, this effect was reduced when used with Sasobit additive. Sasobit additive increased the stiffness and decreased the fatigue parameter at low temperatures. Besides, the results of the LAS test revealed that at high strain values (i.e.> 6%), the fatigue life of CR and Sasobit modified binders was lower than the fatigue life of the pure binder. In other words, CR and Sasobit modified binders could not preserve material integrity.
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İncele - MakaleAçık Erişim2022Scopus SJRQ3Research on the Rheological Properties of Asphalt Binder Modified by Fume Silica and Crumb Rubber Compound
Akpolat, Mustafa; Kök, Baha Vural; Aydoğmuş, Ercan
This study investigates the effect of using Fume Silica (Aerosol 300) alone and together with crumb rubber (CR) in bitumen modification on the traditional and rheological properties of the binder and compares it to the SBS modified binder. Using the aerosol additive in the binder at the rates of 0.5%, 1%, 1.5%, and 2% were determined as the most convenient ratio and CR+aerosol modified binders were prepared per this ratio. The binders were subjected to the softening point, viscosity, frequency sweep, bending beam rheometer (BBR), and Fourier Transform Infrared spectroscopy (FTIR) tests in the context of the study. Besides, the optimum conditions were determined according to the response functions by designing an experiment with statistical regression according to the Response surface methodology (RSM). The results indicate that the optimum aerosol ratio is 1.5%. With the use of 1.5% aerosol in 6% CR modification per bitumen weight, it was found that (1) the softening point increases and the temperature sensitivity decrease in comparison to other binders, (2) the consistency of the binder increases, (3) the complex modulus values increase and become more resistant to rutting, (4) the low-temperature parameters enhance by performing more flexible behavior, (5) there may be physical changes in the structure even though there is no chemical reaction in the binder with the use of CR and aerosol additives, and (6) the experimental data and theoretical data obtained from the RSM method are consistent as per the statistical analysis.
AtıfScopus9WoS7OpenAlex10İncele - MakaleAçık Erişim2021Scopus SJRQ1Investigation on the properties of new palm-oil-based polyurethane modified bitumen
Vural Kök, Baha; Aydoğmuş, Ercan; Yilmaz, Mehmet; Akpolat, Mustafa
Polyurethane-derived polymer synthesized by the reaction of 4.4′-diphenylmethane diisocyanate (MDI) with the new modified palm-oil-based polyol was used as an alternative additive to thermoplastic-elastomers, such as styrene–butadienestyrene (SBS), the most commonly used additive. The study aimed to investigate the effect of polyurethane (PU) modification on the rheological and chemical structure of base bitumen. The softening point, rotational viscosity, dynamic shear rheometer (DSR), multi-stress creep recovery (MSCR), bending beam rheometer (BBR), and Fourier transform infrared (FTIR) tests were conducted on the binders. The effects of curing time and temperature, isocyanate/hydroxyl (NCO/OH) molar ratio, and PU content were examined and the best modification conditions were determined. It was found that 24 h curing conditions at 85 °C were sufficient for the formation of PU bonds and these processes increased the rutting parameter of the binder by 256% compared to 1 h curing. At 50 °C and a frequency of 5 Hz, the binder with a 4:1 NCO/OH ratio had 63% more complex modulus than the binder with a 10:1 NCO/OH ratio. The 7 wt% PU modified binder had the same performance level as 4% SBS modification and 10 wt% PU modified binder was one degree higher. Moreover, above 60 °C, all the PU modified binders gave lower phase angles compared to the 4% SBS modified binder. 7 wt% PU modified binder showed similar elastic properties against cracks at low temperatures compared to the 4% SBS modified binder. The use of palm oil in the synthesis of PU presents an environmentally friendly and cost-effective solution compared to the use of petrochemical derivatives.
AtıfScopus56WoS53OpenAlex60İncele - MakaleAçık Erişim2020Scopus SJRQ1Performance and Aging Characteristics of Hot Mixture Asphalt with Crumb Rubber and Warm Mix Asphalt Additives
Akpolat, Mustafa; Kök, Baha Vural; Yilmaz, Mehmet
In this study, the mixes prepared using crumb rubber (CR) and binders with warm mix additives were aged through various aging methods (1, 2, 3, and 4 weeks at 60 degrees C in the laboratory; 2, 4, 6, 8, 10, and 12 months under the environmental conditions; and AASHTO R30) and examined in terms of performance and aging index. The indirect tensile strength (ITS), indirect tensile stiffness modulus (ITSM), and fatigue tests were applied to the pure and the CR,CR+Sasobit, andCR+Evothermmodified aged and nonaged mixes, and the aging indexes were determined according to the results obtained. According to the test results,CR+Sasobitwas found to be the best mix in terms of mechanical properties. Using the warm asphalt additives in the CR modification was determined to decrease the aging indexes and retarded the aging. Also determined was that a high correlation exists between the aging at 60 degrees C in the laboratory and the aging under the environmental conditions. Based on the fatigue test results, AASHTO R30 short-term aging (4 h at 135 degrees C) was determined to cause structural deterioration in the mixes and yielded low load repetition relative to the pure mixes. Therefore, using this method for the short-term aging of the CR modified mixes would not be appropriate. When the tests applied were evaluated in terms of the aging indexes, the fatigue test was found to be the most sensitive method for detecting aging in the pure mixes and mixes with additives. (C) 2020 American Society of Civil Engineers.
AtıfWoS17OpenAlex15İncele - MakaleAçık Erişim2019Scopus SJRQ1Performance Evaluation of Using Evotherm in SBS Modified Binder
Kök, Baha Vural; Yilmaz, Mehmet; Akpolat, Mustafa
Recently, various types of additives are being used to enhance the properties of bitumen. Until now, few researchers have handled the utilization of different additives in the same binder. In this study, styrene-butadiene-styrene (SBS) and Evotherm were used both separately and in the same blend. Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests were applied to SBS and Evotherm modified binders. SBS and Evotherm were added to pure bitumen in three different ratios. Sixteen different combinations were produced using the two additives, and a pure binder in the same binder was evaluated in the DSR test. Eight different combinations were evaluated in the BBR test. The conclusion reached was that the maximum usage of Evotherm (0.9%) induces a 20% reduction in the rutting parameter of both the 5% and 6% SBS modified binders. The 0.5% Evotherm with 4% and 5% SBS modification does not have an adverse effect on rutting performance. Evotherm modification could prevent the stiffness increment that originates from using the SBS additive, especially at high content. Using 0.7% Evotherm with 4% SBS can acquire the pure binder's low temperature performance. (c) 2019 American Society of Civil Engineers.
AtıfWoS11İncele - MakaleAçık Erişim2019Scopus SJRQ2Effect of gilsonite use on storage stability of styrene-butadiene-styrene modified bitumen
Yalçın, Erkut; Çeloğlu, M. Ertuğrul; Akpolat, Mustafa; Yamaç, Özge Erdoğan; Alataş, Taner; Kök, Baha Vural; Yılmaz, Mehmet
Styrene-butadiene-styrene (SBS) polymer is one of the most preferred additives to improve performance in hot mix asphalt pavements. The storage instability, in other words, the separation of a polymer-rich phase from the bitumen-rich phase in the course of storage and transportation is one of the prevalent problems in SBS modified bitumen. The present study attempted to obtain modified bitumen at the same performance level with the SBS modified bitumen, but stable with respect to the storage stability. For this purpose, both SBS and American Gilsonite (AG) were used in modified bitumen production. It was determined that modified bitumen at the same performance level was obtained with the use of 5 % SBS or 18 % AG in bitumen modification. It was also determined that the performance levels of the modified bitumen obtained with the use of 2 % SBS + 13 % AG, 3 % SBS + 10 % AG and 4 % SBS + 6 % AG were similar. Additionally, 2 %, 3 % and 4 % SBS modified bitumen were used for the assessment of storage stability properties of the SBS modified binders. These 8 different modified bitumen samples were tested for storage stability based on the EN 13399 standard. Penetration, softening point, rotational viscometer, bending beam rheometer, and dynamic shear rheometer tests were conducted on the samples. Based on all conducted tests, it was determined that more stable binders were obtained with the use of AG and SBS in terms of storage stability compared to solely SBS modified bitumen.
AtıfScopus18WoS15OpenAlex15İncele - MakaleAçık Erişim2017Investigation of Low-Temperature Behavior of Stone Mastic Asphalt Mixtures Modified with Paraffin and Crumb Rubber
Akpolat, Mustafa; Kök, Baha Vural; Yilmaz, Mehmet
In hot mix asphalts at low temperatures, cracks occur due to thermal tension and these cracks cause water to leak inside the pavement and the pavement gets deformed sooner than expected. In order to improve the properties of bituminous mixtures, mostly polymer type additives are used in the modification of the bitumen. These types of improvements usually have positive effects on the high-temperature behavior of the mixture. In this study, semi-circular bending test, which is the most commonly used method in the literature to investigate the low-temperature behavior of bituminous mixtures, was performed. In the study, the resistance of stone mastic asphalt mixtures, which were prepared with modified bitumen with a constant 3% of paraffin and various amounts of crumb rubber, to crack formation and its movement was identified. As a result, it was concluded that the effects of additives on crack formation and its movement is varied and the relation between the fractured aggregate surface areas and the fracture toughness of the mixture can be determined by the image processing method.
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İncele - MakaleAçık Erişim2016Scopus SJRQ2Performance evaluation of crumb rubber and paraffin modified stone mastic asphalt
Kök, Baha Vural; Yilmaz, Mehmet; Akpolat, Mustafa
Recently, crumb rubber (CR) obtained from waste tires and Fischer-Tropsch paraffin are mostly used in bitumen modification to improve the performance of bituminous mixtures. Each of these additives affects the different properties of mixtures. There are limited studies in the literature about the combined usage of additive in the same mixture to utilize the different characteristics. In this study, the stability, stiffness, fatigue resistance, permanent deformation resistance, and moisture susceptibility characteristics of the stone mastic asphalt prepared with the bitumen modified with CR and paraffin were examined and compared with the control mixture. It was determined that CR-modified mixtures showed significantly more elastic characteristics. The mixture in which the 10% CR and 3% paraffin were used together gave better results in terms of moisture susceptibility and fatigue resistance when compared with the control mixture. It was determined that the use of paraffin together with CR contributed to the improved performance, and was in accordance with the CR in terms of mechanical characteristics of stone mastic asphalt.
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