• Journal of the Korea Concrete Institute
• /
• v.28 no.4
• /
• pp.481-488
• /
• 2016

Concrete member has been subjected to dead and live loads in use, and the induced stress can affect not only structural but also durability behavior. In mass concrete construction, construction joint are required, however cold joint usually occur due to poor surface treatment and delayed concrete placing. The concrete with joint is vulnerable to both shear stress and chloride ingress. This paper presents a quantitative evaluation of cold joint and loading conditions on chloride diffusion behavior. With increasing tensile stress from 30% to 60%, chloride diffusion coefficient gradually increases, which shows no significant difference from result in the sound concrete. However chloride diffusion coefficient under 30% level of compressive stress significantly increases by 1.70 times compared with normal condition. Special attention should be paid for the enlarged diffusion behavior cold joint concrete under compressive stress.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.23 no.5
• /
• pp.359-370
• /
• 2021

Duct slabs, which are used to build ventilation facilities in underground spaces with transverse ventilation system, need to secure fire resistance according to longitudinal and heavy vehicle traffic of tunnels. This study measured the temperature change at the construction joint of the precast fireproof duct slab which integrates fire resistance material and duct slab under the RWS fire scenario. As a result, it was confirmed that if there is no reinforcement of the construction joint, damage will occur in concrete inside the construction joint, leading to damage to the fireproofing layer. On the other hand, when one side of the construction joint was reinforced with fireproofing materials, it showed more than three times the fire resistance performance compared to when there was no reinforcement. At this time, cross-sectional losses of concrete and fireproofing layer were shown in blocks without reinforcement, but no damage was seen in the reinforced blocks.

• 한국방재학회:학술대회논문집
• /
• 2007.02a
• /
• pp.353-356
• /
• 2007

Asphalt pavements of the airport in service were monitored to construct new runway and taxiway and longitudinal cracks were found on the pavements. The sources of the longitudinal cracks were the low density which was caused by the longitudinal cold joint with asphalt Pavement constructions and the excessive loads of aircraft. Therefore, the echelon paving method using a 12m-wide screed finisher was used to eliminate longitudinal cracks. When the echelon paving is used, construction of the longitudinal joint is changed so that the compaction of the unconfined edge of the first lane is delayed until the second lane is placed. In conclusion, the use of this construction method results in the density of the longitudinal joint being equal to that of the adjacent mat.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.85-86
• /
• 2023

This study confirmed the improvement of the Composite Waterproof Method in which the sheet layer is partially attached with perforated film and the joint is FRP-treated.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.187-193
• /
• 2006

A new jointing method using steel cramps with a unique configuration was developed for the field joint of precast deck slabs of highway bridges. In this jointing method, the looped distribution bars are connected by the cramps to the main reinforcements. Therefore, the joint can transfer the bending moment and shearing force through the interlocking effect caused by the cramps, and it is both excellent in installation on-site and economical compared with the loop joint currently in use. In order to confirm the bending and shear capacities and to clarify the failure mechanism of the joint, a series of static loading tests were carried out. From the results of these experimental studies, it was clarified that the cramp joint has enough load carrying capacity being equivalent to the loop joint.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.13 no.3
• /
• pp.177-197
• /
• 2011

In this study, a series of fire experiments under $HC_{inc}$ and ISO834 (duration of 4 hour) fire scenarios were carried out for three different types of fire protection measures for the segment joint to evaluate their applicabilities to an immersed tunnel. The experimental results revealed that an expansion joint installed to allow relative movements between concrete element ends in an segment joint is the most vulnerable to a severe fire. For the fire protection measure where the originally designed steel plates at an expansion joint arc replaced by fire-resistant boards, the experiments showed that they cannot achieve good fireproofing performance under both $HC_{inc}$ fire scenario and ISO834 (4 hour) fire scenarios since the installation of fire-resistant boards results in the reduction of the sprayed fire insulation thickness. On the other hand, the application of modified bent steel plates replacing the original steel plates was proved to be very successful in fireproofing of the expansion joint due to more sprayed materials filled in bent steel plate than in the original design concept as well as higher adhesion between the steel plate and the sprayed fire insulation layer.

• Journal of the Korea Institute of Building Construction
• /
• v.15 no.2
• /
• pp.185-192
• /
• 2015

Expansion joint is the essential element of the bridge in many cases. When the bridge faces chloride of preventing freezing on the surface of the bridge, the expansion joints is damaged significantly, thus this reduces service life and increases maintenance cost of the bridge. As a solution of this problem, new technology using high ductile materials for the joint without expansion joint was developed and in this research, crack control performance, preventing leaking after the cracking, and chloride resistance were experimentally evaluated. As a result of the experiment, with PCM and FRC materials, the connecting joint suffered poor crack dispersion and severe damage by the chloride penetration while with high-ductile material, the connecting joint dispersed the tensile deformation to microcracks stably up to 7.5mm. Furthermore, under the sever conditions, the leaking was prevented and penetration of chloride ions was prevented after the crack occurred.

• 월간 기계설비
• /
• s.90
• /
• pp.80-82
• /
• 1998

• 한국도로학회지:도로
• /
• v.6 no.2 s.20
• /
• pp.6-11
• /
• 2004

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.147-148
• /
• 2018

Seat waterproofing materials applied to the roof of a building concrete structure inevitably produce joints and are applied with opposite dam joints or overlapping joints depending on the waterproof material applied to the top of the sheet. In this case, the joint performance is determined by the material at the top, rather than by the superimposed joint. In order to solve this problem, various reinforcements have been used to apply to the connecting parts of the opposite dam, but the problem of attachment between different materials or the lack of reinforcement of the joint tape has not been solved. Therefore, for the purpose of securing tensile performance to the joints, this study is used as a reinforcement for the joints of PP materials with high tensile performance and as a reinforcement for nylon materials.