Atık lastik katkılı asfalt kaplamaların trafik gürültüsünü sönümlemedeki etkileri
The effects of scrap tires in asphalt pavement on highway noise damping
Yazar: CELAL TOLGA İMAMOĞLU
Danışman: PROF. DR. ZÜBEYDE ÖZTÜRK
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Ulaştırma Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2012
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
Bu çalışmada öncelikle tezin amacına yönelik temel bilgileri sağlamak amacıyla temel ses kavramları, sesin fiziksel özellikleri, ses düzey tanımları hakkında bilgiler verilmiştir. Bu temel bilgiler sonrası karayolu kaynaklı gürültü ve bu gürültüyü oluşturan etmenler incelenmiştir. Ayrıca yine amaca yönelik olarak atık lastiklerin birleşimi, genel özellikleri, potansiyel çevresel riskleri ve yönetimi hakkında kapsamlı bilgiler sunulmuştur.Atık lastik katkılı asfaltın tanımı, kullanımı, performansı ve faydaları hakkındaki bilgiler verildikten sonra empedans tüpü ASTM E1050 ile gerçekleştirilen laboratuvar deneyi ile atık lastik katkılı asfaltın birleşenlerindeki değişimin ses sönümlemesindeki etkileri ayrıntılı bir şekilde incelenmiştir. Böylece atık lastik katkılı asfaltın ses sönümlemedeki davranışı ve bu davranışı etkileyen faktörler analiz edilerek tez çalışmasının temeli oluşturulmuştur.Çalışmanın son bölümünde ise öncelikle Türkiye'deki atık lastik durumu mevcut yasa ve yönetmeliklere göre incelendikten sonra İSFALT A.Ş ve TÜBİTAK MAM `ın ortak çalışması olan atık lastik katkılı asfaltın bitümlü sıcak karışımlardaki performansı ve Karayolları Genel Müdürlüğünün 1.5 km'lik pilot kauçuk asfalt uygulaması gibi ülkemizde gerçekleşen ilk projelere değinilmiştir. Son olarak atık lastik katkılı asfalt kaplamanın diğer bir trafik gürültüsü önlemi olan ses perdeleriyle birlikte kullanılmaları durumunda ses perdeleri inşa maliyetlerinde azalmaya ve efektif ses sönümlemesi sağlamasına yardımcı olacağı sonucuna varılmıştır.

Abstract:
Noise is defined as unwanted or excessive sound. At a minimum, it can cause discomfort, and it has the potantiel causethe potential to cause severe physical and psychological damages. Historically, traffic noise has been indentified as a continuous environmental problem that affects the quality of human life.The increase in the world population not only caused the number of vehicles to increase, but has also lead to bigger sized vehicles; to accommodate for the transportation of increased human supplies. Even though newer vehicles are designed to produce lower noise levels, the increase in vehicle density has kept traffic noise as a major setback in the improvement of the quality of life. In the last few decades, the population growth in the United States has increased from 180 million residents in 1960 to 293 million in 2005 (FHWA 2005). This indicates a need for more homes, more roads, and in most cases, more and heavier vehicles.For the past four decades, the crumb rubber modified (CRM) binder has gaining popularity in use. It is based on mixing crumb rubber particles obtained from recycled shredded tires with conventional (unmodified) asphalt binders. CRM binders have beenused in producing many pavements around the world, in which results indicates that they had excel in their performance over conventional pavements. However, not all benefits of CRM mixtures have been evaluated.There have been many claims that adding rubber to asphalt reduces the noise generated by traffic however, this has not been properly evaluated.In order to provide a basis for this thesis, this study will first present an informative background on basic sound concepts, sound level definitions, and physical properties of the sound. This introduction will be followed by an examination of the sources of highway traffic noise. The source of highway traffic noise may be classified into three categories: noise generated from the interaction between tires and pavements, noise generated from the engine and exhaust, and noise generated by the aerodynamic nature of the vehicle. Noise generated by the tire/pavement interaction is the dominant contributor to highway traffic noise. Also, many factors enhance the noise at the tire/pavement interaction, thus increasing the efficiency of the noise energy. After this part, comprehensive information on the basic properties of waste tires and their composition has been, followed by a discussion of waste tire management and environmental risks it carries.The definition of the scrap tires in asphalt, and a discussion of its use, performance, and advantages has been followed by an analysis of a lab experiment and the effect of the change in the composition of crumb rubber asphalt in sound absorption. The laboratory setting was used to minimize the effects of the different variables affecting the noise development in the field. A method called the impedance tube or standing wave method has been standardized by the American Society for Testing and Materials, ASTM E1050, ?Standard Test Method for Impedance and Absorption of Acoustical Materials Using A Tube, Two Microphones and A Digital Frequency Analysis System?. In addition, the International Organization for Standardization, ISO 10534-2,?Acoustics- Determination of Sound Absorption Coefficient and Impedance in Impedance Tubes- Part 2?, has been developed to determine the acoustical properties of materials. The principle of this method is based on measuring the wave reflection of a pavement core after sending a sound wave toward the sample. The effects of the properties such as: aggregate gradation, aggregate size, aggregate type, tire type, vehicle type, pavement condition, temperature, traffic volume on noise were not measured. These factors were not considered because either the mechanism of their effects has already been proven by previous research, or these factors could not be studied by the proposed method. Thereby, the behavior of crumb rubber asphalt in sound absorption and the factors influencing this behavior has been examined, providing the basis of this thesis.The OGFC mixtures are more efficient than dense mixtures in reducinghighway traffic noise. The reduction was attributed to the higher permeability of the OGFC mixes when compared to dense mixtures. However, findings suggested that for the same aggregate gradation, as binder content increased, permeability decreased, therefore sound absorption decreased. The crumb rubber grinding procedure and the sources of binder used in this study had no effects on the sound absorption of the mixtures. No statistical differences between the sound absorption of the dense mixtures were found. Asphalt film thickness and modification did not have a statistical effect on sound absorption. The sound absorption coefficients were very small, indicating that the effects of binding material are minimal. On the other hand, air void size had statistically significant effects on sound absorption. That is, as the air void size decreases, the inner surface area (for the same air void percent) increases, therefore, the sound absorption increases. Laboratory aging had no effect on sound absorption. Furthermore, volumetric measurements indicated that the air void percent had increased after aging. The findings indicated that the thickness of the samples had statistically significant effects on sound absorption. The effects of porous specimen thickness on the high frequency at which peak absorption occurred were found to be statistically significant. Dense mixtures produce significantly higher sound levels than porous mixtures. The effects of crumb rubber were not as significant as mixture type; however, the mixes that produced significantly lower sound levels contained high concentrations of crumb rubber. Asphalt film thickness, air void percentage, porosity, and resilient modulus did not yield any significant correlations with sound absorption. Having smaller air void sizes increases the sound absorption as more energy is lost due to the higher friction of the smaller air voids. However, permeability should be kept at its highest levels since decreasing the air void size also decreases permeability. Dense pavement thickness affects sound absorption. For low speed roads (50km/hr), there is an optimum thickness that will yield the highest sound absorption. For porous pavements (i.e., OGFC), the thickness that yields the highest sound absorption depends on the pavement permeability. For higher permeability pavements, a thicker pavement is recommended. However, if permeability is low, reduced pavement thickness might yield higher sound absorption coefficients. For porous pavements, increasing permeability will shift the location of the peak absorption to higher frequencies. In addition, for low speed roads,decreasing the pavement thickness will shift the location of the peak absorption to higher frequencies.In the last part of this study, the situation of waste tire management in Turkey has been assessed according to the current law and regulations. Rubber and Rubber Modified Bitumen Specifications Dimensions of Asphalt Mixtures as of the date written thesis prepared by Karayolları Genel Müdürlüğü although the unit price bid for completed stages of the rulers are not used more. The co-project of ISFALT A.S. and TUBITAK MAM. on the performance of crumb rubber asphalt on bitumen hot mix and the pilot application of 1.5 km rubberized asphalt by the General Directorate of Highways are projects that has been referred to in this section. Finally, it has been concluded that the use of crumb rubber asphalt in conjunction with sound walls results in the reduction of construction costs and it helps increase sound absorption capacity. To make the application more robust economic analysis of the "Hedonic Price Technique" approach. This approach is equivalent to within 1 dB of noise (A) ² change of property is affected by the road caused by a change rate in proportion to 0.9% is assumed. This change, "Damage Cost?. According to the data is the optimum solution to 2m high concrete noise barrier. 1km long, 2m high concrete noise barrier applied to the geometric parameters of the road hard mold, selecting the design of a 5-cm layer of abrasion, in Turkey in the coming days which will start production of rubber additives for asphalt bitumen Barya Construction Machinery Agricultural Automotive San. Internal and Dış.Tic. When we use the unit prices of the company 5dB'lik Co.Ltd noise for sound damping construction costs were spent on screens 70 000,-TL, rubber modified asphalt pavement is the additional cost of 15 552,-Euro turned out to be. Results of traffic noise from existing noise barriers damping crumb rubber reinforced asphalt coating application practices revealed that the optimum cost is relatively reduced.Widely applied in the world and especially in the U.S. scrap tire reinforced asphalt overlay, pavement next to improve the performance of waste tires produced for moving vehicles on highways with the arrival of the state to prevent environmental pollution and other highways, such as traffic noise that occurs due to the reduced environmental impact. Which will occur in the transport cycle, such as environmental and noise pollution, measures to reduce environmental impacts, such as curtains in this application compared to existing noise in the world to bring great advantages in terms of costs often imply the use of this reason. Specifications and regulations necessary infrastructure in our country has been prepared for this application karayollarımızda crumb rubber blended asphalt applications is expected to commence in the progressive period.