• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.439-447
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• 2011

Longitudinal cracks due to traffic truck loadings that are caused by local deformations of steel orthotropic bridge decks are sometimes observed in the wearing surface. So, underlying causes of the longitudinal pavement crack induced by structural behaviors of steel decks are investigated in this study. For this purpose, The rational finite element model of the steel deck and the pavement having the box girder is developed and a parametric study is performed by varying thickness or elastic modulus ratios of both the steel deck plate and the pavement. As a result, a large tensile strain above the webs of the u-rib and the box girder, which becomes the main cause of the cracks of the pavement, is detected from variation of the normal strain component of the wearing surface in the transverse direction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1043-1051
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• 2017

Asphalt overlay on deteriorated concrete pavement has a problem of early damage due to reflective cracking. There is a need for a new method capable of reducing reflection cracking and ensuring the durability of pavement. The purpose of this study was to obtain durability of asphalt overlay with stress absorbing membrane interlayer (SAMI) using epoxy asphalt binder. The tensile performance, durability, water resistance and bonding performance of Epoxy-SAMI were evaluated by various tests. As a result of tests, Epoxy-SAMI meets the quality standard of the bridge waterproofing material. The repeated direct tensile test was carried out to investigate the effect of reflective cracking reduction. When the Epoxy-SAMI was applied, it had 1.2~1.56 times higher reflective cracking resistance than PSMA asphalt concrete with the thickness of 10cm even if the section thickness decreased. 4-point bending beam test results showed the number of fatigue failures increased 7.5 times when Epoxy-SAMI was applied. The Epoxy-SAMI was found to be effective in improving the durability of the asphalt pavement overlay because it serves to prevent reflective cracking, increase lifespan, and function as a waterproof layer.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.103-114
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• 2011

Usage of bicycle has been supported the universal reduction of energy consumption and $CO_2$. For the same purpose, new constructions for long length bike roads are planned in Korea. Recently, laboratory tests of physical properties and resistance against environmental loading about optimum mix design of roller compacted concrete, that have advantages of high structural performance by cement hydration and aggregate interlocking, simple construction procedure and low construction cost, are performed for the effective construction of new bike roads. However, properties of roller compacted concrete had different results between laboratory and field tests since it had different compaction method. Also, construction method of roller compacted concrete are not defined for the application of bike roads since it had different demand performance such as thin pavement thickness, low strength and etc with road pavements. Thus, in this experimental research was launched to evaluate the core properties, visual inspection, compaction ratio, water content, thickness reduction rate of roller compaction, skid resistance and roughness by experimental construction about variable mix proportion and compaction method based on laboratory test results. And construction method of roller compacted concrete pavement were suggested for the application of bike roads.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.272-278
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• 2016

Porous pavements are recommended as a Low-Impact Development (LID) method which is a strategy to develop a water cycle as close to a natural state as possible, and to solve the urban impervious surface problems. Porous pavements can yield a solution if it provides a more permeable surface with extra space to contain extra water from building roofs. But there are few applications in Korea because of a lack of recognition and experience. Highway engineers are mainly concerned about the infiltration of water into pavement structures. They worry about the weakening of the asphalt mixture and subgrade, and freezing during the winter season due to the infiltration of water. Meanwhile, hydrological experts doubt the effects of the amount of water to control during the flooding season, and environmental experts prefer a non-point pollution treatment system established beside highway. In this study, from reviewing the history and the body of literature about porous pavements, conclusions regarding the most advanced technologies were made. First, traditional thickness designs can be used for porous pavement, no extra distresses was found by weakening and freezing during the winter season. Second, hydrological design can be made by controlling the thickness of the pavement and the outlet of water. Third, the treatment efficiency of non-point pollution of porous pavements is not worse than any other method. Importantly, it's a more eco-friendly solution because of its lower requirement for de-icing agents.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.143-153
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• 2006

The differences in the stress distribution and the critical stresses in concrete pavement systems were analyzed when the dual-wheel single-, tandem-, and tridem-axle loads were applied at the interior and the edge of the pavement. The effects of the concrete elastic modulus, slab thickness, foundation stiffness, and tire contact pressure were investigated. The stresses under the interior loads were calculated using the transformed field domain analysis and stresses under the edge loads were obtained using the finite element method. The critical stresses under the interior and the edge loads were compared with respect to various parameters and the equations to predict the ratio between the stresses under the edge and the interior loads were developed and verified. From this study, it was found that the trends of the changes in the critical concrete stresses under the interior and the edge loads were very similar and the critical stress locations under those loads were identical. The critical stress ratio, which was obtained by dividing the critical stress under the edge loads into that under the interior loads, decreased with increasing the number of axles. That ratio became larger as the concrete elastic modulus increased, the slab thickness increased, the foundation stiffness decreased, and the tire contact pressure increased.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.57-68
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• 2008

The stabilization techniques in the pavement foundations have advantages in increasing pavement performance and reducing pavement thickness. By mixing the geomaterials and stabilizer, the economical and structurally sound layer can be added in the pavement system. Until now, these techniques have been applied in the field empirically and the design criteria for stabilization has not been established. The purposes of this paper are to evaluate the mechanistic properties of stabilizers used for geomaterials and determine the type and optimum amount of stabilizer for each technique. The unconfined compressive testing and repeated load resilient modulus test were conducted on the coarse grained soils mixed with various types of stabilizer to investigate the strength and deformation characteristics of stabilized geomaterials. It is found from the test that the unconfined compressive strength of stabilized geomaterials is more than ten times higher than that of gradation modified geomaterials. The resilient modulus of stabilized geomaterials increases by $6{\times}10$ times compared to the original soils and tends to increase with increase of volumetric and deviatoric stress, and amount of stabilizer.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.143-152
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• 2009

The purpose of this study is to evaluate the freezing index and frost penetration depth. The freezing index and frost penetration depth were analyzed using air temperature and temperature profile of pavement system in Korea LTPP-SPS(Long Term Pavement Performance-Specific Pavement Study) site. The predicted frost penetration depth were then compared with the measured one from the LTPP sites. And the trend of annual freezing index was analyzed using the temperature data of meteorological stations located in the vicinity of Korea LTPP-SPS site. The result showed that the freezing index was rapidly decreased since 1987, and it was known that the use of freezing index determined from the past 30 years temperature data could cause the over estimates in the pavement thickness design. The temperature profile measured at 3 sections of LTPP-SPS sites showed that the temperature of subbase layer was above $0^{\circ}C$, even though anti-frost layers were found in these sections. Comparing the measured and calculated frost depth, the frost depth calculated from the subgrade frost penetration permissible method showed a similar trend with the measured frost depth.

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.1-13
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• 2013

This paper presents the results of a laboratory investigation of the porous pavement substructure effect when reinforced with geocell. In order to analyze load carrying capacity of Geocell, a series of 9 reduced-scale laboratory tests was performed, changing the type, thickness, diameter of Geocell. The results of the analyses indicated that the bearing capacity of the reinforced Geocell increases much more than the non-reinforced Geocell and load carrying capacity was considered to be insignificant according to the type of Geocell. It was also found that the most supportive effects appeared as 30 cm in diameter and 1.8mm in thickness.

• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.1-10
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• 2013

The main objective of this research is to develop the Mechanistic-Empirical (M-E) guidelines for evaluating the capacity of existing highways to sustain route overweight truck traffic over a specified performance period due to a growing concern on the impact of increasing overweight truck loads on highways. In this study, a two-stage framework was developed for this purpose. Level I procedure involves the use of pavement evaluation charts to identify the best possible route from among the alternatives considered and to determine what additional tests and analyses are needed as a screening tool. Level II involves the application of the Overweight Truck Route Analysis (OTRA) program to evaluate the structural adequacy of an existing route to carry routine overweight truck traffic over the specified performance period along with estimating asphalt concrete overlay thickness, if necessary.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.91-96
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• 2010

The purpose of this study is to find problems about pedestrian road of tourist resort and to make new type of sidewalk pavement with wood chip and binder using urethane resin on the parks and tourist resort. The wood chip pavement has new economics and durability with comfortable texture. Samples of these pavement materials were tested for tensile strength, permeability and ball rebound value. Also, after immersion for 24 hours, tensile strength, samples' thickness and weight were measured and discussed the strength reduction according to the water immersion. Tensile strength experimentation was examined on dry condition and water immersion. The result of examination on dry condition was 1.06MPa and on water immersion was 0.67MPa. The results showed 36.8% decreasing rate of tensile strength. Permeability experiment test based on field permeability method of pavement were conducted as a result, permeability coefficients were in the range of 0.67~0.78mm/s that all exceeds object permeability coefficient. Elasticity experiment was based on elasticity test method of Japan road association. GB coefficient was 21% and SB coefficient was 10%. GB coefficient and SB coefficient increased if fine aggregate were increased.