• International Journal of Highway Engineering
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• v.16 no.4
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• pp.21-33
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• 2014

PURPOSES: The purpose of this study was to break away from the workforce method using cold-mix asphalt mixtures and has a constant quality and has develop repair materials of pre-production asphalt-precast types. METHODS: The selection of the repair material was determined as the results obtained through physical properties of materials and the field applicability. In case of repair materials, values obtained through Marshall stability test & the dynamic stability test & retained stability test as well as the site conditions was considered. In case of adhesive, test results were obtained through examination of the bond strength(tensile, shear) and the field applicability of the adhesive was examined through combined specimens to simulate field applications. RESULTS : According to the results of laboratory tests, in the case of repair materials, Marshall stability and dynamic stability, retained stability of cold-mix reaction type asphalt mixture is the highest. In the case of adhesive, two-component epoxy-urea has a very high bonding strength(tensile, shear) was most excellent. According to the results of field tests, when epoxy-urea was excellent workability. Also, the repair body through actual mock-up test did not occur large deformation and fracture after 12 months. CONCLUSIONS : A suitable repair material is cold-mix reaction type mixture of asphalt-precast, a suitable adhesive is a two-component epoxy-urea.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.115-123
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• 2011

This study was conducted to investigate the early-age behavior and performance of precast pavements constructed by replacing existing asphalt pavements for an intersection in urban bus only lanes. The monitoring items included level differences between asphalt pavement and precast panels at the beginning and ending locations of the precast pavement, level differences and joint widths between precast panels, precast panel settlement, and skid resistance of the panel surface. At a certain time after the construction, the diamond grinding method was applied and its effect was also investigated. The monitoring results showed that as time went by, the panel level, joint width, settlement, and skid resistance were not much varied. That implied the stable sustaining of external loads by the precast pavements. In addition, it was verified that employing diamond grinding could reduce the level differences between precast panels.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.229-237
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• 2011

This study was conducted to investigate the early-age performance of precast pavements constructed by replacing existing asphalt pavements for a bus stop section in urban bus only lanes. The behavior monitoring items included the differences in the levels between asphalt and precast pavements at the entrance and exit of the precast pavement, joint widths and level differences between precast slabs, slab settlement, and skid resistance at the slab surface. The applicability of diamond grinding techniques was also investigated. The results of this study showed that the slab level, joint width, settlement, and skid resistance were not much changed as time passed, which implied that the precast pavements stably sustained vehicle loads. It was also found that employing diamond grinding could much improve the leveling between precast slabs and the surface skid resistance.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.256-260
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• 2010

It has been proved that precast slab track has advantage of rapid construction speed and good quality compared to in-situ concrete slab track. A korean precast slab track, which is named as a K-PST, was developed and had been installed on the embankment and explored on the air. The developed track system consists of precast track panel and underpouring layer which is made of cement-asphalt mortar. Consequently, poor filling of underpouring layer directly could affect on the long-term performance of the track system. As a preliminary study, the effect of the poor infilling of the underpouring in precasst slab track system on structural behavior was investigated through FEM analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.44-45
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• 2020

The purpose of this study was to contemplate the effectual waterproofing materials and construction methods for the restoration of underground infrastructures using precast arches(PC-Arch). Until now, there were no proper waterproofing guidelines for waterproofing precast arch tunnel when restoring cultural heritage or building underground infrastructures for noise control. Asphalt membrane sheets were commonly used, but the efficacy of waterproofing done on the precast segment was vulnerable. This study aims to examine the Synthetic Rubber Polymerised Gel(SRPG) proposed in ISO TR 16475, a guideline for the repair of water-leakages, and to demonstrate field applicability based on the waterproofing solution used on the road improvement project in front of Changgyeonggung Palace in Yulgok-ro, Seoul, Republic of Korea.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1273-1278
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• 2007

The cement-asphalt mortar is a mixture of cement and asphalt emulsion, and is utilized as a underpouring materials for the railway track which is used to fill under slab panel space so as to provide a stabilized track support and a tool for reduction of noise and vibration. To increase the workability of grouting, this study investigates the effect of temperature on cement-asphalt mortar by analyzing its physical and mechanical properties before/after hardening according to the temperature (10, 15, 20, 25, $30^{\circ}C$). According to the test results, it is found that as for the physical property of fresh cement-asphalt mortar the more mixture temperature become higher or lower, the more fluidity become worse. But by increasing reducing agent amount and its unit quantity, the required fluidity is met. The compressive strength as physical property of hardened cement-asphalt mortar become lower when temperature is lower but taking it by and large the physical properties of cement-asphalt mortar before/after hardening aren't so affected by temperature and well satisfy the requirement. And it has proved that rate of expansion and freezing and thawing resistance aren't affected by temperature.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.35-36
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• 2018

Korea has many problems due to the asphalt pavement or impermeable pavement. Many methods are being implemented to improve water circulation. Among them, permeable packaging materials are used. However, existing permeable packaging materials have a problem of causing efflorescence and clogging the pores. The pores of the permeable packing material are clogged and the permeability is lost. This leads to economic problems and product problems. The purpose of this study was to develop a block to prevent efflorescence.