• International Journal of Highway Engineering
• /
• v.9 no.4
• /
• pp.227-236
• /
• 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.

• International Journal of Highway Engineering
• /
• v.13 no.4
• /
• pp.133-142
• /
• 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 Korea Academia-Industrial cooperation Society
• /
• v.19 no.4
• /
• pp.571-577
• /
• 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.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.987-992
• /
• 2009

Continuous Compaction Control is a new cutting edge technique in United States, Japan and European construction market that uses an instrumented compactor to measure soil stiffness in real time usually with vehicle tracking system such as Global Navigation Satellite System (GNSS). In this study, soil stiffness was evaluated by adapting Fourier transforming technique with acceleration data obtained from accelerometers used as a continuous compaction control instrument. The soil stiffness obtained by accelerometers gave analogous results with reference results such as dry density, elastic modulus obtained from Geogauge and Light falling deflectometer.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2002.02a
• /
• pp.15-22
• /
• 2002

본 연구에서는 타이어의 공기압이 농용트랙터의 견인성능과 토양다짐에 미치는 효과를 실험적으로 조사하였으며, 다음과 같은 결과를 얻었다. 1) 타이어공기압에 따른 트랙터의 견인성능 실험 결과, 공기압의 감소는 트랙터의 운동저항은 감소시키고, 견인력과 견인효율은 증대시키는 것으로 나타났다. 따라서 연약지에서 운용되는 트랙터는 공기압의 조절을 통해(최소 허용 공기압까지 타이어공기압의 감소를 통해) 견인성능과 작업성능을 향상시킬 수 있을 것으로 판단된다. 2) 트랙터의 타이어공기압과 통과횟수의 증가는 모두 토양다짐을 증가시키는 것으로 나타났다. 따라서 토양다짐을 줄이기 위해서는 트랙터가 통과한 궤적상을 연속해서 통과할 수 있도록 작업 계획을 세우면 전체 경작 면적에 대한 토양 다짐을 줄일 수 있을 것으로 판단된다. 또한 타이어의 공기압을 최소 허용 공기압 수준까지 감소시킬 경우 토양다짐을 최소화할 수 있을 것으로 판단된다. 3) 위의 결과로부터 트랙터의 작업성능의 향상과 토양다짐의 최소화는 타이어공기압의 조절을 통해 어느 정도 이를 수 있는 것으로 판단된다. 따라서 이러한 목적을 달성하기 위해서는 운전석에 설치된 제어판을 통해 지면의 상태에 따라 타이어의 공기압을 운전자가 쉽게 조절할 수 있는 최첨단 기술인 CTI시스템을 농용트랙터에 적용하는 연구가 필요한 것으로 판단된다.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.1
• /
• pp.43-48
• /
• 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.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.636-643
• /
• 2008

The objective of this paper is to assess the potential use of the geogauge and the light falling weight deflectometer (LFWD) and the soil impact hammer as quality control/quality assurance $Q_C/Q_A$ devices for compacted soil layers. A comprehensive field experimental program considering variation of number of compaction, water contents and thickness of compaction layer was conducted on compacted layers of gravel sand. The geogauge, LFWD, the soil impact hammer and static load test (PLT) as a reference test were performed for the compacted layers. The geogauge elastic modulus, $E_G$, the LFWD dynamic modulus, ELFWD, empirical soil stiffness, $K_{30}$, obtained from soil impact hammer and soil stiffness directly obtained from PLT, $K_{30}$, were correlated with increasing number of compaction. The results of this study show that the geogauge, LFWD and the soil impact hammer, which are very simple to test, can be used as substituting devices for static PLT which is a conventional quality control/quality assurance $Q_C/Q_A$ devices for compacted soil layers.

• International Journal of Highway Engineering
• /
• v.11 no.4
• /
• pp.127-132
• /
• 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 Korean Geotechnical Society
• /
• v.36 no.12
• /
• pp.45-56
• /
• 2020

In this paper, intelligent compaction (IC) technology and the earthwork quality control specifications based on IC were analyzed, and the field study was conducted to investigate the relationship between the representative IC value CMV (Compaction Meter Value) and spot test results (plate bearing test and field density test). As the number of roller passes increased, both the CMV and spot test results increased. However, point-by-point comparison between CMV and spot test results yielded poor quality correlations; this is because the ununiform stiffness of the underlying layer and the moisture content of the lift layer affected the CMV and spot test results, respectively. Most international specifications related to IC requires knowledge of the IC values and their relationships with the soil properties obtained by the traditional spot tests. Therefore, for the successful implementation of intelligent compaction technology into earthwork construction practice, the number of roller passes as well as the lift thickness and the moisture content of the soil should be carefully considered.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.16 no.2
• /
• pp.271-279
• /
• 1998

This paper discusses the development of compaction management system using Real Time Kinematic (RTK) GPS technology for the efficient management or compaction. The use or RTK provides the land surveyors with a graphical display of his/her corrected position on the ground at that moment in time. In this work, we intended to improve the efficiency of compaction management showing the route of rollers and the total number of compaction obtained from management software (GPSROLL v.1.0) developed in this study. The RTK GPS system installed on the roller. To improve the efficiency of field management, GPSROLL software provides also data processing module for the field soil test and the field surveying data. GPSROLL system is based on the Korean GUI for user-friendly data input and output.