• Title/Summary/Keyword: gyratory compactor

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EVALUATION OF SLAG MIXTURE PROPERTIES USING GYRATORY COMPACTOR

  • Lee, Kwan-Ho
    • International Journal of Highway Engineering
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    • v.1 no.2
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    • pp.135-154
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    • 1999
  • Compaction of asphalt pavement is one of the important processes to make good quality one. There are many laboratory-compaction methods to simulate field compaction, including Marshall compaction, Hveem compaction, gyratory compaction, and etc. The most common method used to determine the fundamental properties of asphalt mixture for design is Marshall method which is using impact energy. However, there is major difference between field compaction using kneading compaction and Marshall compaction using impact energy. Therefore, the gyratory compactor, which currently is the best to simulate the field compaction, was employed. The fundamental properties of asphalt specimen compacted by gyratory compactor and Marshall compactor were determined using laboratory test. From the tests, slag mixture with carbon black or pyrolyzed carbon black showed better performances, such as, in low susceptibility to temperature, high resistance against water and rutting, and high resilient modulus and indirect tensile strength.

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Characteristic of Subgrade Soil using Gyratory Compactor (선회다짐기를 이용한 노상토의 다짐특성)

  • Lee, Kwan-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.571-577
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    • 2018
  • A gyratory compactor was developed to reflect the field compaction roller, which is commonly used in road construction. Unlike the compaction of the proctor using a conventional impact load, the gyratory compactor simulated the field roller compaction characteristics using the compressive force by the roller weight and the shear force through the rotation of a roller. The purpose of this study was to evaluate the shear stress and density change characteristics during compaction, which are difficult to obtain in the existing compaction process of the proctor, and to utilize it as a basic data for road design. The compaction characteristics of sand and subgrade soils were also analyzed and evaluated using the gyratory compactor. The compaction characteristics obtained using the gyratory compaction are basically the number of gyrations, height of the specimen, compaction density, void ratio, degree of saturation, and shear stress. As the number of gyrations increased, the height of the specimen decreased, the compaction density increased, the void ratio decreased, the degree of saturation increased, and the shear stress tended to increase. The shear stress of the compacted specimens started at 200 kPa in the initial stage of compaction and increased to approximately 330 to 350 kPa at 50 gyrations. The compaction density, degree of saturation and shear stress tended to increase with increasing water content in the same specimens. Compaction using turning compaction has the advantage of measuring the physical properties required for road design, such as density and shear stress, so that more engineering road design will be possible if it is reflected in road design.

Evaluation of Rutting Performance of Hot Mix Asphalt with Compaction Curve of Gyratory Compactor (선회다짐기 다짐곡선을 이용한 아스팔트 혼합물의 소성변형 특성 평가)

  • Park, Tae-Seong;Lee, Byung-Sik;Hyun, Seong-Cheol;Lee, Kwan-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.3
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    • pp.59-67
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    • 2007
  • For the time being, HMA test specimen were prepared by Marshall Compaction Method for hot mix asphalt design and evaluated the mechanical properties of HMA at the specified air voids. Gyratory Compaction can simulate the field compaction process and measure the degree of compaction just after field compaction in laboratory. Superpave mix design with Gyratory compactor has been used for characterization of performance. The curve of gyratory compaction can be used to evaluate the permanent deformation potential of hot mix asphalt. In this paper, couple of indices for hot mix asphalt have been showed for hot mix asphalt in Korea. The major properties from gyratory compaction curve are compaction energy index and traffic compaction index. The specific guide line for the potential of hot mix asphalt has been proposed.

Analysis of Technical Problem for Soil Compaction by Gyratory Compactor (선회다짐기를 이용한 흙의 다짐시 기술적 문제 분석)

  • Lee, Kwan-Ho;Jang, Tae-Young
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.43-48
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    • 2010
  • Proctor test A or D method of compaction is the most common laboratory test for investigation of subgrade soil characteristics, however, compression type using roller is used in the field. The differences between laboratory and field compaction have considerable error as application to subgrade soil properties of laboratory test. The investigation of compacted soil is carried into effect to solve the problem. The gyratory compactor which is made to reproduce the field density of asphalt mixture, coming from traffic loads, has an advance to compact it similar to arrangement of field aggregate particles. This gyratory compactor has several problems of investigation of compacted soil, because it has designed to make initial asphalt specimens. The main objectives of this research are grasping problems when compacted soil test using the gyratory compactor and showing solutions. It has made a comparative study of difference of the percentage of water content and weight, which are before and after compaction, about the pressure of compaction, frequency of compaction and speed of compaction. And it also has investigated finding maximum percentage of water content which not occur change of percentage of water content after compaction and searching how has an effect on drawing compaction curve.

A Study for Selecting the Design Number of Gyration of Gyratory Compactor (선회다짐기의 설계 다짐횟수 선정을 위한 연구)

  • Kim, Boo-Il;Lee, Moon-Sup
    • International Journal of Highway Engineering
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    • v.9 no.4
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    • pp.227-236
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    • 2007
  • The design number of gyration is required in the process of asphalt mix design using gyratory compactor. The purpose of this study is to select the design number of gyration for asphalt mix design in the laboratory. Three types of methods were used to select the design number of gyration. The first method is to select the gyration number which gives the same density with the mixtures compacted with 75 blows of Marshall Compaction. The second method is to select the gyration number which gives the same deformation strength with the mixtures compacted with 75 blows of Marshall Compactor. The third method is to select the gyration number which meet the 4% air voids. Ten mixtures, one type of aggregate(granite), one type of asphalt binder(pen. 60-80), and 10 types of gradation, were prepared for the laboratory tests. As a result, 100 number of gyration was selected for the design number of gyration of the asphalt mix design. This result shows a similar trend with the design number of gyration used in the foreign countries. Thus, the design number of gyration selected in this study can be used for the asphalt mix design using the gyratory compactors.

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Feasibility Evaluation of Number of Gyration for HMA and WMA Mixtures (HMA와 WMA 혼합물의 선회 다짐횟수 적정성 검토 연구)

  • Lee, Moon-Sup;Yoon, Chun-Joo;Kwon, Soo-Ahn;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.133-142
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    • 2011
  • The objective of this study is to validate the number of gyrations of Superpave gyratory compactor(SGC) for compaction of hot-mix asphalt (HMA) and warm-mix asphalt(WMA) mixtures. Marshall compaction was also used for comparison purpose. The 13mm and 19mm aggregates of 1st class quality shape were used. A PG64-22 and a PG76-22 for HMA and a PG70-22 for WMA. Four compaction temperatures based on the suggested value were used for each binder using 100 gyrations for SGC and 75 blows per side for Marshall compactor. It was found that SGC compaction was somewhat better than Marshall compaction. The analysis of variance showed that two compactors were significantly different in air voids of 19mm mixtures at ${\alpha}=0.05$ level. The 13mm mixture did not show a significant statistical difference. When compacted at the temperature below a certain level, however, the compaction of two compactors were fond to be proor. Therefore, observing compaction temperature above the minimum level is important to secure proper compaction work. If the minimum temperatures were maintained, 100 gyrations, which was given for HMA of arterial road pavement by the Korean Guide, was found to be appropriate compaction, showing similar or better compaction work than 75 blows per side of Marshall compaction.

Evaluation of Compaction Properties of Subgrade Soil by Gyratory Compaction Curve (선회다짐곡선특성을 이용한 노상토의 다짐도 평가)

  • Lee, Kwan-Ho;Cha, Min-Kyung;Lim, Yu-Jin
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.1
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    • pp.33-40
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    • 2009
  • Compacted soil are used in almost roadway construction with compaction of soil. The direct consequence of soil compaction is densification, which in turn results in higher strength, lower compressibility, and lower permeability. The standard and modified Proctor tests are the most common methods. Both of these tests utilize impact compaction, although impact compaction shows no resemblance to any type of field compaction and is ineffective for granular soils. It has been dramatic advances in field compaction equipment. Therefore, the Proctor tests no longer represent the maximum achievable field density. The main objectives of this research are a survey of current field compaction equipment, laboratory investigation of compaction characteristics, and field study of compaction characteristics. The findings from the laboratory and compaction program were used to establish preliminary guidelines for suitable laboratory compaction procedures.

Comparison and Evaluation of Dynamic Modulus of Hot Mix Asphalt with Different Shift Factors (전이함수 결정법에 따른 아스팔트 혼합물의 동탄성계수 비교평가)

  • Kim, Hyun-Oh;Lee, Kwan-Ho
    • International Journal of Highway Engineering
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    • v.7 no.1 s.23
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    • pp.49-61
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    • 2005
  • The dynamic modulus of hot mix asphalt can be determined according to the different combinations of testing temperature and loading frequency. The superposition rule is adapted to get the master curve of dynamic modulus for each hot mix asphalt. There are couple of different methods to get the shift factor which is a key for making the master curve. In this paper, Arrehnius, 2002 AASHTO, and experimental method was employed to get the master curve. Evaluation of dynamic modulus for 25mm base course of hot mix asphalt with granite aggregate and two asphalt binders(AP-3 and AP-5) was carried out. Superpave Level 1 Mix Design with gyratory compactor was adopted to determine the optimum asphalt binder content(OAC) and the measured ranges of OAC were between 4.1% and 4.4%. UTM was used for laboratory test. The dynamic modulus and phase angle were determined by testing on UTM, with 5 different testing temperature(-10, 5, 20, 40, & $55^{\circ}C$) and 5 different loading frequencies(0.05, 0.1, 1, 10, 25 Hz). Using the measured dynamic modulus and phase angle, the input parameters of Sigmoidal function equation to represent the master curve were determined and these will be adopted in FEM analysis for asphalt pavements. The shift factor and activation energy for determination of master curve were calculated.

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