• 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 Therefore, the Proctor tests no longer represent the maximum achievable field density.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.

• 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.

• 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.

• Magazine of the Korean Society of Agricultural Engineers
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• v.29 no.2
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• pp.64-73
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• 1987

효과적인 모래의 다짐 방법으로 진동에 의한 방법이 널리 사용되고 있다. 이 연구의 목적은 모래의 진동 다짐시 영향을 주는 인자의 개별적인 효과를 분석하고 가 인자들이 복합되어 진동다짐에 주는 효과를 분석하는 것이다. 이 연구에서는 진동시간 가속도 과도화중 염수비 시료의 다짐전 밀도등을 변화시켜가며 진동테이블 위에서 제작된 시료를 다짐하였고 시험결과는 상대밀도의 변화애 의하여 분석하였다 진동다짐의 효과는 다짐가속도 진동수 및 모래의 정도에 따라 변하며 과도하중이나 진건은 비교적 적은 영향을 주는 인자였다. 가속도가 1g 보다 큰경우 다짐효과는 진동이 시작되는 초기에 발생하였고 그 후는 면밀하게 진동효과가 나타났다. 효과적인 다짐을 위하여는 최적가속도와 최고 과도하중의 선택이 중요하며 최적치보다 큰경우는 다짐의 효과가 감소한다. 건조된 모래와 포화된 모래 모두 같은 최적가속도에서 최대의 다짐효과를 나타냈다. 각 인자 즉 가속도 진동수 단위 중량 영수비, 균등계수, 유효압경, 과도하중, 및 진동시간등의 효과를 복합하여 진동다짐의 효과를 상대밀도의 변화로 나타낼경우$\Delta$DR=38.0∧0.14 의 관계를 얻었다.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.127-132
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• 2009

This study presents the test results on the compaction characteristics of warm mix asphalt mixtures that include the additive in 3 different mixtures(hot mix asphalt, SBS and SMA). The tests were conducted to find out the compaction characteristics on the compactability with varying compaction time, different amount of the warm mix additive and lowering the compaction temperature. The Superpave gyratory compactor was used to find out the variation of the density when the number of the gyration is varied. A dense mixture and 3 different warm mix additives were employed to find the relationship between compactability and compaction time. The comparison of the compactability with lowering the temperature was conducted using dense mixture, SBS polymer modified mixture and stone matrix asphalt mixture(SMA). The difference of the density of warm mix asphalt mixtures was not found due to the lowering of compaction temperature when it was compared with the standard mixture and the warm mix showed the stable condition in density. In the mean time, depending upon the different warm mix additive and mixture, the difference of density and the variation trend of compaction is found to be existed and shows the relationship between these two variables.

• 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.

• 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.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.11-20
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• 2018

Surplus soil is commonly used at construction sites, because suitable fill material is not always immediately available and leads to additional costs. However, most surplus soils do not meet the requirement of suitable fill material to achieve the stability and strength of embankments. In this study, Proctor compaction tests and field compaction tests were performed by installing geosynthetics to resolve the problems caused by compacting unsuitable soils. Compaction energy and the number of geosynthetics were changed under the type A- and D- and type A Proctor compaction tests (KS F 2312), respectively. The field compaction testing using geosynthetics was performed on surplus soils of high water content. Optimum water content and maximum dry density of compacted soil decreased and increased by reinforcing geosynthetics, respectively. Compaction curves behaved with geosynthetics as the compaction curves behaved with higher compaction energy. Efficient compaction was possible because the compaction energy increased to 2.10 and 2.71 times the compaction energy required to achieve the same maximum dry density with one and two geosynthetic layer(s), respectively. Furthermore, field compaction tests verified that efficient compaction was possible because the dry density of unsuitable surplus soils of high water content was increased by reinforcing geosynthetics.

• International Journal of Highway Engineering
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• v.3 no.4 s.10
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• pp.127-136
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• 2001

To increase the structural integrity of concrete box culvert good compaction by the dynamic compaction roller with bi9 capacity is as effective as good backfill materials. It is needed for effective compaction that a compaction roller closes to concrete structure with high frequency. However structural distress of the culvert could be occur due to the excessive earth pressure by great dynamic compaction load. To investigate the characteristics of Induced stress by compaction, a box culvert was constructed with changing cushion materials and compaction methods. Two types of cushion material such as tire rubber chip and EPS(Expanded Polystyrene) were used as cushion panels and they are set on the culverts before backfill construction. Laboratory test result of cushion material says that the value of dynamic elastic modulus of rubber is lesser than that of EPS. On the other hand, material damping of rubber material is greater than that of EPS. In most case, dynamic compaction rollers with 10.5 ton weights were used and vibration frequency was applied 30Hz for the great compaction energy. This paper presents the main results on the characteristics of dynamic earth pressures during compaction. The amounts of induced dynamic pressures$(\Delta\sigma\;h)$ by compaction are affected with construction condition such as compaction frequency, depth of pressure cell, distance between roller and the wall of culvert and roller direction. Based on the measured values dynamic lateral pressure on the culverts, it could be said that orthogonal direction of roller to the length of culvert is more effective to compaction efficiency than parallel direction.

• 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.