• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.279-288
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• 2010

Recently, researches on the performance warranty contracting has been going on to improve construction quality in road pavement area. The performance warranty contracting gives construction companies opportunity to select materials and methods freely while asks them to maintain a certain level of performance during a given period. To introduce the performance warranty contracting in Korea, lots of research results on performance indicator and threshold value of asphalt pavement have been made to be included in the warranty specification. However, research effort on the performance indicator and threshold value of concrete pavement which is commonly constructed in expressway and national highway has not been enough. In this study, the warranty duration, performance indicator, and threshold value of the concrete pavement were investigated by reviewing literatures on cases of the performance warranty contracting in European countries and states of the US. Major distresses influencing the performance of jointed concrete pavement were investigated and analyzed to be compared to the warranty duration, performance indicator, and threshold value of foreign countries.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.603-610
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• 2017

Various type of pavement deterioration such as crack, bumpy, pothole is rapidly increasing according to the accelerated environmental changes like heavy rainfall, frequent snowing, difference temperature, etc. Accident related to pothole that cause fatal traffic accidents has been increased more than five times over the next five years starting from 2008. As direct or indirect damage by pothole which caused injuries and car damages increases every year, quicker and more efficient management measures are necessary. This study presents the algorithm for materials quantity take-off. The algorithm was suggested by correlation in pothole size and area. Suggested algorithm were confirmed the validity through the 15 field survey in capital area. According to the results of survey, usually the residual materials at which 5~7 kg was generated decreased to 1~2 kg. It showed that automatic pothole detection system is expected not only to reduce materials and resources, but also to contribute to quality improvements of pavement through more accurate material take-off from the situation of constructing rely on their own judgement.

• Computers and Concrete
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• v.19 no.4
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• pp.435-442
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• 2017

In recent years, the use of supplementary cementing materials, especially in addition to concrete, has been the subject of many researches. Rice husk ash (RHA) is one of these materials that in this research, is added to the roller compacted concrete as one of the pozzolanic materials. This paper evaluates how different contents of RHA added to the roller compacted concrete pavement specimens, can influence on the strength and permeability. The results are compared to the control samples and determined optimal level of RHA replacement. As it was expected, RHA as supplementary cementitious materials, improved mechanical properties of roller compacted concrete pavement (RCCP). Also, the application of adaptive neuro-fuzzy inference system (ANFIS) in predicting the permeability and compressive strength is investigated. The obtained results shows that the predicted value by this model is in good agreement with the experimental, which shows the proposed ANFIS model is a useful, reliable, fast and cheap tool to predict the permeability and compressive strength. A mean relative error percentage (MRE %) less than 1.1% is obtained for the proposed ANFIS model. Also, the test results and performed modeling show that the optimal value for obtaining the maximum compressive strength and minimum permeability is offered by substituting 9% and 18% of the cement by RHA, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.3
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• pp.69-81
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• 1988

The Repeated Load Triaxial and Oedometer Tests to the weathered granite & silty clay soil have been fulfilled to investigate their dynarnic characteristics. The results obtained are summarized as follows ; 1. In the relation between the repeated triaxial compression and the oedometer test, the recoverable strain of weathered granite soil showed a tendency to decrease by the increase of the repeated loads number(N), and that of silty clay showed approximately constant values while the total strain increased continuously. 2. The changes of plastic strain was dependent to the level of deviator stress which is the most important element in the calculation of soil deformation under repeated load condition. And there was a significance of 10% between the level of stress and plastic strain. 3. When the soil was aimost dried or saturated to 100%, the deformation by the repeated loads was small. However the deformation showed peak around the saturation of 50%. 4. When the deformation was predicted by the repeated triaxial load tests of a laboratory, it is desirable to introduce the threshold stress concept in the calculation of deformation of subgrade of the pavement. 5. The improved design equation (Eq. 16) introducing the modulus of conversion(Fo), which is based on the Boussineq' s theory, is considered to be rational in the design of flexible pavement. From the above results, the deformation to the repeated traffic loads could be predicted by the repeated triaxial tests on the pavement materials or undisturbed soil layers, therefore it is think that the durable and econornic pavement could be constructed by reflecting that to the design.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.607-612
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• 2002

In road pavements, it is known that cement concrete pavement has superior durability, safety compared. But in repairing pavement, cement concrete pavement is not usually applied because of the length of time while the road is interrupted when using Ordinary and Rapid-hardening Portland Cement. And Super High Early Strength Cement and Ultra Super High Early Strength Cement are not favorable for ready mixed concrete because of rapid setting time, high slump loss and other restrictions. We developed special cement developing 1 day strength of over 30.0N/mm$^2$ to open the road within 1 day and workable time is maintained over 1 hour so that it can be used as ready mixed concrete. We performed experimental overlay construction with the cement and evaluated the mechanical property and the durability. At curing temperature of 8-l8$^{\circ}C$,the flexural strength was 6.4N/mm$^2$at 1 day, so that the road can be open to traffic within 1 day. In durability test, the hardened concrete showed higher durability than Portland cement concrete.

• International Journal of Concrete Structures and Materials
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• v.19 no.1E
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• pp.17-23
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• 2007

In rainy weather, permeable concrete pavement has advantages such as good drainage, increased skid resistance, reduced splash and spray behind vehicles for improving the safety of driving vehicles as well as reduction of the traffic noise. It also contributes to improvement of traffic environment. In this study, the fundamental properties of permeable concrete in accordance with maximum size of aggregate, sand percentage and unit cement content were investigated for practical use of permeable concrete pavement. Although the permeability standard for typical permeable asphalt-concrete pavement is $1{\times}10^{-2}cm/sec$, the researchers determined that the coefficient of permeability of the permeable concrete should be set higher at $1{\times}10^{-1}cm/sec$. Then, the researchers measured the coefficient of permeability, strength, void ratio, and continuous void ratio of the permeable concrete while varying maximum size of the aggregate, sand percentage, unit cement content for detailed analysis. It was found that the void ratio, continuous void ratio, and flexural strength were about 15%, 12%, and 5.0MPa, respectively, when the permeability of the concrete was set at $1{\times}10^{-1}cm/sec$. Given that the maximum size of aggregate was $10{\sim}13mm$, we reached the conclusion that the best mix design for permeable concrete was $0{\sim}20%$ of sand percentage and $380kg/m^3$ of unit cement content.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.9-17
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• 2009

Most of the current drainage criteria have been developed on the basis of experimental field results and theoretical analyses of infiltration under saturated conditions. The objective of this study is to extend the understanding of pavement drainage systems by considering unsaturated condition in the sublayers. Analyses of unsaturated flows through pavements was performed by running finite element program(SEEP/W) with a range of pavement materials and drainage parameters. Meanwhile, the widely used DRIP program developed by FHWA is based on assumption of saturated condition of pavements. Differences between saturated and unsaturated condition in the sublayers of the pavements are verified. It is verified that for unsaturated conditions time to drain would take longer time compared to saturated condition.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.31-41
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• 2019

More than 90% of roadway in the world are paved as asphalt concrete pavement due to its excellent properties compared with other paving materials; excellent riding quality, flexibility, anti-icing property and easy maintenance-ability. In this study, to make best use of the softer property of the asphalt mixture, the flexible sand asphalt mixture (FSAM) was developed for pedestrian ways. The mix design was conducted to prepare FSAM using PG64-22 asphalt, screenings (sand) less than 5mm, crumb rubber, hydrated lime and limestone powder without coarse aggregate. The deformation strength ($S_D$), indirect tensile strength (ITS) and tensile strength ratio (TSR) tests were conducted to make sure durability of FSAM performance. The impact energy absorption and flexibility were measured by drop-boll test and the resilient modulus ($M_R$) test. The impact energy absorption of FSAM was compared with normal asphalt pavement, concrete pavement, stone and concrete block for pedestrian way. As a result of drop-boll test, FSAM showed higher impact energy absorption compared with other paving materials with the range of 18% to 43%. Impact energy absorption of FSAM increased with increasing test temperature from 5 to $40^{\circ}C$. The results of $M_R$ test at $5^{\circ}C$ showed that the flexibility of FSPA was increased further, because the $M_R$ value of the sand asphalt was measured to be 38% lower than normal dense-graded asphalt mixture (WC-1). Therefore, it was concluded that the FSAM could provide a high impact absorbing characteristics, which would improve walking quality of the pedestrian ways.

• International Journal of Highway Engineering
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• v.9 no.2 s.32
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• pp.141-151
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• 2007

The current standards and specifications for the road pavement construction have been developed based on materials and construction methods. The pavements constructed in accordance with those specifications do not guarantee high performance of pavements since they do not consider long-term performance of pavements. Therefore, as part of the study to develop performance-based construction standards for pavements, the payment adjustment methods based on the pavement performance are currently being developed. This paper presents preliminary studies performed to develop the payment adjustment methods when there is deficiency in the concrete slab thickness that is one oi the most important factors for the pavement design and construction. First, the payment adjustment methods in USA were investigated. Then, the AASHTO failure equation, the relationship between slab thickness and stress, and the relationship between stress level and pavement life were employed to propose the payment adjustment concepts based on the pavement performance for the deficient slab thickness. The variation in the slab thickness according to measurement locations was investigated by taking cores. In addition, the measurement methods of slab thickness and the variation of measured thicknesses depending on performers were analyzed, and finally the methodology to develop the thickness deficiency ranges for the use in the payment adjustment methods was proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.77-85
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• 1992

Layer material properties of asphalt concrete changes with climatic conditions. Pavement design and analysis should be performed in the representative climatic condition that gives standard physical properties of pavement layer materials. In this study, an evaluation procedure of pavement design temperature is proposed and programed based on damage effect analysis using fatigue failure criterion. Three regions, Seoul, Daegeon, and Pusan, are chosen to obtain the representative climatic data of South Korea. Domestic pavement design temperature is developed by applying the proposed algorithm to 6 domestic pavement section models with the respective regional climatic data. Asphalt concrete pavement failure criterion is also proposed for the condition of developed domestic pavement design temperature. The design temperature for the region of South Korea is estimated as $l7^{\circ}C$, which is converted to $23.6^{\circ}C$ for the AC surface layer temperature. It is found that the procedure to determine design properties of AC surface layer material at $20^{\circ}C$ gives overestimated results of AC moduli for the domestic pavement system. From the comparison study, it is also found that the estimated pavement design temperature is similar to the result of SHELL Design Chart.