• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.97-109
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• 1983

In this study, the effects on the soil compaction were investigated through the various testing method by changing the number of layers, the number of blows per layer and drop height. The results obtained in this study were summarized as follows. 1. Soil compaction was largely influenced by maximum grain size of soil in case of small testing mold diameter. 2. The compaction effect showed best in the well graded soil. In this test, compaction effect showed the best value in the soil which contained about 30~40% of particles finer than No. 200 sieves although it would vary according to the content of coarse grained soil. 3. Though the compaction method was changed at the level of compaction energy fixed, the effect of soil compaction showed little. 4. The increment of compaction energy increased the effect of soil compaction, but over a certain limit the soil compaction showed little on the effect. 5. In the method to increase the compaction energy for the purpose of the most reasonable effect, the soil compaction effect was differently shown according to the grain size distribution of the soil.

• Geotechnical Engineering
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• v.10 no.4
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• pp.5-16
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• 1994

This paper is concerned with the engineering characteristics weathered mudstone soil in Pohang area. The crushability of weathered Boil can be described in terms of the ratio of surface area(Sw'/Sw). In this study, the characteristics of weathered mudstone soil was investigated by performing teat such as compaction. CBR, permeability, and grain size according to compaction energy. The results are found as follows : (1) In generally, the specific gravity of weathered mudstone soil is very small and optimum moisture content (OMC) is large and maximum dry density is small (2) The CBR value increases as the compaction energy increases, but this value decreses from D -2 compaction(26kg.cm/cm3). the swelling ratio increases the npaction energy to 20.6kg.cm/cm" and decreases in all compaction energy from 20.6kg.cm/cm3 (3) As the compaction energy is small, the change of permeability due to water content is large and the difference between minimum coefficient of permeability and coefficient of permeability at OMC is large, but the difference is small as the compaction energy increases (4) The decrease of permeability due to the decrease of void ratio and the increase of ratio of surface area is caused by the crush of particle due to the increase in compaction energy. Especially, the compaction energy is smaller, the change of the ratio of surface area to the coefficient of permeability is larger.rger.

• Geomechanics and Engineering
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• v.9 no.2
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• pp.261-273
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• 2015

In the present investigation, a series of laboratory compaction and unconfined compressive strength laboratory tests has been performed. To determine the effect of compaction energy, type of sand, and fly ash content, compaction tests have been performed with varying compaction energy ($2700kJ/m^3-300kJ/m^3$), types of sand, and fly ash content (0% to 40%) respectively. From the experimental results, it has been found that the optimum value of unconfined compressive strength obtained for a sand-fly ash mixture comprised of 65% sand and 35% fly ash. Based on the data obtained in the present investigation, a linear mathematical model has been developed to predict the OMC of sand-fly ash mixture.

• Journal of the Korean GEO-environmental Society
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• v.16 no.8
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• pp.13-20
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• 2015

Due to the population growth and exhaustion of resource, the development on the harsh environment such as cold weather is emerging as an alternative for new resource development. The permafrost area covers about 14 percent of the world's land area and the global construction market for such area is rapidly expanded. Whereas the developed countries have already recognition of the need for research of coldest place and invested heavily in technology development, the domestic technology for the coldest place development is less developed and related research has rarely been performed. There is not a detailed national specification standard for the strength and deformation properties of the earthworks at sub-zero temperature but simple field directions. Therefore, the D compaction tests were conducted on the sand with fine contents of 0%, 5%, 10% and 15% at room temperature ($18^{\circ}C$), $-3^{\circ}C$ and $-8^{\circ}C$ to investigate the effect of the compaction energy on the compacted soils at sub-zero temperatures. Based on the test results, the larger compaction energy, the larger maximum dry unit weight under sub-zero temperature and D type compaction at $-3^{\circ}C$ show similar max. dry unit weights as those obtained from the compaction at the room temperature. However, compaction at $-8^{\circ}C$ showed significant performance degradation regardless of the compaction energy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.2
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• pp.81-103
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• 1979

The weathered granite soil involves problems in its stability in soil structures depending upon the reduction of soil strength due to the water absorption, crushability, and content of colored mineral and feldspar. As an attemt to solve the problems associated with soil stability, the crushability of weathered granite soil was investigated by conducting tests such as compaction test, CBR test, unconfined compression test, direct shear test, triaxial compression test, and permeability test on the five soil samples different in weathering and mineral compositions. The experimental results are summarized as follows: The ratio of increasing dry density in the weathered granite soil was high as the compaction energy was low, while it was low as the compaction energy was increased. The unconfined compressive strength. and CBR value were highest in the dry side rather than in the soil with the optimum moisture content, when the soil was compacted by adjusting water content. However, the unconfined compressive strength of smples, which were compacted and oven dried, were highest in the wet side rather than in soil with the optimum moisture content. As the soil becomes coarse grain, the ratio of specific surface area increased due to increased crushability, and the increasing ratio of the specific surface area decreased as the compaction energy was increased. The highest ratio of grain crushability was attained in the wet side rather than in the soil with the optimum moisture content. Such tendency was transforming to the dry side as the compaction energy was increased. The effect of water on the grain crushability of soil was high in the coarse grained soil. The specific surface area of WK soil sample, when compacted under the condition of air dried and under the optimum moisture content, was constant regardless of the compaction energy. When the weathered granite soil and river sand with the same grain size were compacted with low compaction energy, the weathered granite soil with crushability had higher dry density than river sand. However, when the compaction energy reached to certain point over limitation, the river sand had higher dry density than the weathered granite soil. The coefficient of permeability was lowest in the wet side rather than in the optimum moisture content, when the soil was compacted by adjusting soil water content. The reduction of permeability of soil due to the compaction was more apparent in the weathered granite soil than in the river sand. The highly significant correlation coefficient was obtained between the amount of particle breakage and dry density of the compacted soil.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.27-33
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• 2015

PURPOSES : To ensure appropriate RCC properties with sufficient strength development and workability, it is necessary to secure a proper level of consistency. It is also necessary to secure maximum dry density, which is an important factor for increasing the interaction of aggregate interlocking, leading to an augmentation of RCC strength. On the other hand, the dry density of RCC can be changed owing to the compaction conditions, water content, and particle size distribution. A Proctor test and a modified Proctor test were used for determining the optimum water content needed to achieve maximum dry density with different amounts of compaction energy. A Vebe test, on the other hand, was used for checking the level of consistency, which is important for producing a workable mixture. METHODS : To confirm the degree of compaction at various particle sizes, RCC mixtures with different sand/aggregate ratios were evaluated. The Proctor test and modified Proctor test were applied to these mixtures to check the effect of the aggregate gradation and compaction energy on the maximum dry density and optimum water content. During each test, three specimens were produced for all types of water content under each aggregate gradation. A compaction curve and the optimum water content and maximum dry density for each aggregate gradation were then obtained for both tests. The range of water content for the appropriate consistency of each aggregate gradation was determined through a Vebe test. The optimum water content was then evaluated based on this range. RESULTS : The compaction test results show that the modified Proctor test provides a higher maximum dry density and lower optimum water content compared with the standard Proctor test. For the modified Proctor test, two cases of aggregate gradation (s/a = 30% and 70%) had the optimum water contents outside of the appropriate water content range. For the standard Proctor test, on the other hand, none of aggregate gradations provided the optimum water content within the desired range. CONCLUSIONS : The modified Proctor test should be used for an RCC mixture design because it can provide adequacy between maximum dry density and consistency. Moreover, the compaction roller has become highly developed for higher compaction energy.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.141-148
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• 2001

Dynamic compaction is the ground improvement method by applying the impact energy. This impact energy can damage to adjacent structure in urban area. Therefore, if dynamic compaction method is applied, careful attention should be payed to surrounded structures. In this study, the method was performed in waste landfill and the frequency of vibrations were measured according to each distances, drop-heights, and vibrating directions. The measured data show that particle velocity bas low frequency and it is greatest in longitudinal direction. There was little differences between Maynes suggestion and measured data. Therefore, Maynes suggestion can be adopted if the range of vibration can be predicted. Also, It was found that minimum 45m distance is needed in order to satisfy the administrative code if dynamic compaction method is applied.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.89-99
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• 2009

In order to clarify the relation between the physical properties and the strength parameters of compaction materials and to develop a method for evaluating the strength parameters required for design from the physical indices including void ratio and dry density, compaction test, one-dimensional compression test, and exhausted-drained triaxial compression test were carried out with decomposed granite soils. The test results showed that the specimens became over-consolidated by compaction and the increase of the strength parameters of the specimens by the increase of the compaction energy could be verified quantitatively. A method for the evaluation of strength parameters from the void ratio of soil after compaction using preconsolidation theory which evaluates over-consolidation of materials was developed and its engineering applicability was tested for verification.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1037-1047
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• 2013

A systematic laboratory compaction testing was performed with the laboratory seismic measurements of the compacted specimens sampled from various compaction fills and was supplemented with in-situ seismic testing to investigate the effects of compaction energy on the elastic wave velocities of the railway roadbed materials. The both variances of the compressive and shear wave velocities with moisture content curve ($V_p$-w and $V_s$-w curves) are similar to the general trend of the density-moisture content curve(${\gamma}_d$-w curve). At the wet side of optimal moisture content (OMC), either $V_p$ or $V_s$ does not significantly increase, which is well reflecting the no gaining in density with the increasing compaction energy exceeding modified-D compaction effort. $V_p$ increases linearly with ${\gamma}_d$ at the dry side of OMC, while it does exponentially at the wet side. The in-situ wave velocities were found to be influenced by the level of confinement and $V_s$ was more sensitive to compaction energy than $V_p$.