• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.268-276
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• 2008

In highway construction projects, concrete pavement productivity has been challenged with constructors and decision-makers; at present there are few methods available to accurately evaluate the factors impacting on it. Any inefficient method to analyze it leads to the excessive schedule, higher rehabilitation costs, shorter service life, and reduction of ride quality. To implement these negative outcomes, constructors or decision-makers need a systematic tool that can be used to categorize the factors related to construction productivity. This paper applies multiple regression technique for productivity analysis of the Jointed Plane Concrete Pavement (JPCP), identifies the significant factors, and provides a predictive model assisting in monitoring and managing the productivity of the JPCP construction process. The completed and progressive projects are employed to derive and assess the proposed model. The results are analyzed to illustrate its capabilities.

• Structural Engineering and Mechanics
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• v.52 no.4
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• pp.829-841
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• 2014

The main purpose of this study is to determine the effect of overlay on the crack propagation. In order to simplify the problem, a cement concrete pavement is modeled as an elastic plate on Winkler foundation. To derive the singular integral equations, the Fourier transform and dislocation density function are used. Lobatto-Chebyshev integration formula, as a numerical method, is used to solve the singular integral equations. The numerical solution of stress intensity factor at the crack tip is derived. In order to examine the effect of overlay for resisting crack propagation, numerical analyses are carried out for a cement concrete pavement with an embedded crack and a concrete pavement with an asphalt overlay. Results show the significant factors that influence the crack propagation.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.886-891
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• 2005

The frequent maintenance required on some asphalt concrete (AC) pavement sections has made reconstruction with Portland Cement Concrete Pavement (PCCP) a feasible alternative. However, many constructability issues need to be addressed in order to realize the full potential of this alternative. Accelerated paving encompasses three classes of activities: methods to accelerate the rate of strength gain, methods to minimize the construction time, and traffic control strategies to minimize user delay. Three major AC intersections with severe rutting problems were reconstructed with PCCP. The entire reconstruction of each intersection, including demolition of the AC pavement and its replacement with PCCP, took place over a period of three days, starting on Thursday evening and opening the intersection to the traffic on Sunday afternoon. This paper discusses the use of PCCP for accelerated reconstruction of major urban intersections with minimal user and traffic disruption, using innovative construction techniques and traffic management optimization principles and demonstrates that concrete pavements can be constructed efficiently and quickly.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.105-114
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• 2006

A popular alternative to extend the life of aged pavement is asphalt overlay. However, it has a very serious and inherent shortcoming in deterring a reflection crack. Although joint-rehabilitation and stress-relief techniques have been applied to deter such reflection cracks in aged pavement, the techniques had a limited success only in slowing down the progress of a reflection crack. Rubblization technique rubblizes the concrete pavement slab in situ and uses the rubblized slab as the base material. Then, pavement overlay is applied to finish off the rehabilitation of aged pavement. This rubblization technique has the advantage of solving the problem of reflection cracking completely. When rubblization technique is applied, the upper layer of aged concrete pavement is rubblized between 40mm-70mm in depth. However, the lower layer is typically rubblized more than 100mm in depth. Nevertheless, it is difficult to turn the entire concrete pavement of more than 30cm in depth into rubblized aggregate of appropriate size. Thus, a simulation experiment was carried out to find the appropriate rubblized depth, which avoids the reflection cracking and still maintains the function of subbase, by varying the depth of rubblized depth in loom increments of 0cm, 10cm, and 20cm. The result indicated the optimum rubblized depth was 10cm (Lee, 2006). Additionally, a small rubblizinge equipment was developed in order to derive the rubblization technique appropriate for thick concrete pavement. This equipment was tested out on an experimental pavement, which was constructed with the same standard and specification for the road in actual use, by varying its rubblizing head shape and energy as well as the effective area of rubblization. This experiment led to a prototype equipment for rubblization of thick concrete pavement. The prototype was put into use on a highway, undergoing a test construction and monitoring afterwards. This entire process was necessary for the validation of the proposed rubblization technique.

• International Journal of Highway Engineering
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• v.16 no.5
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• pp.39-47
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• 2014

PURPOSES : This study aimed to analyze economic effect of recycled aggregate production on job-site airport pavement. METHODS : The validation of site recycling for waste concrete as economic efficiency is analyzed through the case study of site recycling at an O airport pavement construction. The break-even point for the cost of site recycling was estimated according to two different waste concrete processing methods such as job-site recycling and processing on commission (or plant). RESULTS : Job-site recycling cost decreases as the use rate of job-site recycled concrete aggregate increases, or the amount of concrete waste increases, but transporting distance decreases. It was shown in an O airport case that as the use rate of job-site recycled concrete aggregate exceeds 61.4 %, the job-site recycling cost is cheaper than the processing cost on commission. CONCLUSIONS : The results of this study can utilize basic data of feasibility for site recycling of waste concrete on airport pavement construction.

• International Journal of Highway Engineering
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• v.2 no.3
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• pp.145-153
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• 2000

Pavement evaluation is a fundamental component for rational pavement management. Optimal rehabilitation method and the priority of rehabilitation should be based on the evaluation data. Some types of pavement condition index are needed for objective evaluation of Pavement condition and management of road network. In this study a expressway concrete pavement condition index model is developed through regression analysis that correlates panel rating with distress measurement from the test sections. The derived condition index can be used for network level PMS for the expressway concrete pavement. Correlation coefficient of the model was 0.68. The selected independent variables were International Roughness Index, crack and area of patching.

• Computers and Concrete
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• v.11 no.2
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• pp.169-182
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• 2013

One of the major benefits of the pre-stressed concrete pavements is the omission of tension in concrete that results in a reduction of cracks in the concrete slabs. Therefore, the life of the pavement is increased as the thickness of the slabs is reduced. One of the most important issues in dealing with the prestressed concrete pavement is determination of the magnitude of the pre-stress. Three dimensional finite element analyses are conducted in this research to study the pre-stress under various load (Boeing 777) and thermal gradient combinations. The model was also analyzed under temperature gradients without the presence of traffic loading and the induced stresses were compared with those from theoretical relationships. It was seen that the theoretical relationships result in conservative values for the stress.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.200-204
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• 1994

Low temperature associated damage mechanism is not well known for asphalt concrete. Many studies have related the thermal cracking of pavement in the roadway in cold region with overall shrinkage of the pavement surface under assumption of homogeneous material. This study, however, was intiated based on the assumption that thermal incompatibility of materials (heterogeneous) in asphalt concrete mixture would be the primary cause of the damages. Acoustic emission technique and microscopic obsevation were employed to evaluate damage mechanism of asphalt concrete due to low temperature. The first method showed the sufficient evidence that asphalt concrete could be damaged by lowered temperature only. The second method showed that the damage by temperature resulted in micro-cracks at the interface between asphalt matrix and aggregate particle. It was concluded that these damage mechanisms were the primary cause of major thermal cracking of asphalt pavement in cold region.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.253-254
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• 2009

This study was conducted to estimate deterioration reason of jointed concrete pavement. Image analysis tests were performed according to ASTM C 457 using concrete core specimens. Durability factors were estimated according to spacing factor, which is related with air content and air-void information. Test results show that spacing factors of most specimens were estimated above 250$\mu$m so that investigated concrete pavement has the problem of freeze and thawing resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.98-101
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• 2003

The Alkali-Aggregate Reaction (AAR) may cause a serious failure in the concrete structures. Several researchers in some nations have performed the continuous studies to prevent failure of a concrete structures by the AAR distress as well as the studies to manifest the mechanism. The ASTM Standards to prevent failure by potential AAR aggregates were established in 1950. The KS F2545 and KS F 2546 were established to test the susceptibility of aggregate to potential AAR in 1982. But the researches on the AAR have not been performed affluently in Korea because the distress due to AAR has seldom been reported officially. In this study, the Chemical Method and Scanning Electron Microscopy (SEM) were used to verifying the cause of the pattern crack on the surface and internal crack in the plain concrete pavement. It can be concluded that the distress of a specific site in plain concrete pavement was mainly due to AAR, and the chemical method and SEM may be the effective tools for verifying the cause of AAR distresses.