• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.175-176
• /
• 2018

In this study, the performance of acrylate was evaluated by using acrylate composite waterproof sheet. Through this experiment, the waterproof sheet plays a primary role of waterproofing. When the water leakage occurs, the acrylate reacts with water and expands, and the performance of the self repairing of the damaged part is confirmed by temperature.

• Journal of the Korean Society of Safety
• /
• v.16 no.2
• /
• pp.91-96
• /
• 2001

Theoretical definitions of mixed behavior of PE panel and connote should have preceded to cause a mixed behavior of connote and polyethylene which have different elastic module, one-line expansion coefficients, poison ratios, compressive strengths and tensile strengths. Consequently, changes are analyzed through experiment process to identify the effects on interpretation of mixed behavior on the basis of temperature change of structures, temperature rise of concrete other than PE panel due to hydration heat temperature rise of concrete other than PE panel due to drying and contraction, working of hydrostatic pressure by storage and temperature gradient From the results of interpretation of the analysis, it is concluded that PE panel have slight influences on the change of guess of structures and maintains structural stability compared with concrete structures without PE panel.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.2
• /
• pp.127-135
• /
• 2011

In this study, the engineering characteristics of outer wall insulation panels according to type of insulation materials, their combination, and the contents of insulation materials were tested. Vermiculate, ceramic bead, perlite and expanded polystyrene were used as insulation materials. Flexural strength and thermal conductivity depending on the insulation materials used were measured. It was found that the flow of fresh mortar significantly decreased with an increase in the contents of insulation materials. In terms of the effect of insulation materials on thermal conductivity, an increase in insulation materials resulted in a decrease of thermal conductivity. In particular, PL and EPS, when used together, have lower thermal conductivity than other materials. Regarding the flexural strength of the hardened mortar, the strength showed a tendency to gradually decrease according to the increase in contents of insulation materials, compared to that of the plain mortar. In terms of the flexural strength depending on various types of insulation materials and its combination, it was found that the flexural strength of cement mortar containing 3% of vermiculate(V)+ceramic bead(CB)+perlite(PL) was the highest among the specimens tested.

• Korean Journal of Materials Research
• /
• v.25 no.11
• /
• pp.590-597
• /
• 2015

In this article, poly methyl triethoxy silane was compounded with an inorganic waterproof admixture at a certain ratio to improve the performance of gypsum products; a new type of high-efficiency compound water-proofing additive was also investigated. Furthermore, the waterproof mechanism and the various properties on the hardened gypsum plaster were investigated in detail by XRD and SEM. The results show that the intenerate coefficient of gypsum plaster increased to more than 0.9; the water absorbing rate decreased to less than 10 %. Both the bending strength and the compressive strength of gypsum plaster increased by various degrees. The intenerate coefficient reached a maximum value of 0.73 and the strength of the samples showed almost no change when 5% cement alone was added. In this new type of the high-efficiency compound with waterproof additive, the optimal technological parameters for formulas were obtained to be: 5% cement, 18 % mineral powder, and 0.8% poly methyl triethoxy silane, to compound gypsum plaster. Meanwhile, the production of high performance gypsum as a building material has become possible.

• Journal of the Korea Institute of Building Construction
• /
• v.21 no.1
• /
• pp.87-95
• /
• 2021

In this study, seven companies(A~G) designated as new construction technology selected and evaluated KS F 2622: Method of test for performance evaluation of membrane roofing systems that are similar to field application conditions. As a result of the test, it was confirmed that although all test specimens exceeded KS standards in the basic physical, it was difficult to obtain field quality performance in weak areas such as joints and vertical parts of the adhesive coating method in water-tightness, sagging resistance, swelling resistance tests except for fatigue(crack behavior) tests.

• Journal of the Korea Institute of Building Construction
• /
• v.19 no.1
• /
• pp.19-29
• /
• 2019

In this study, a revised oil leakage evaluation method for assessing oil leakage stability of asphalt mastics used in upper slabs of below-grade residential parking lots was developed and presented. In order to verify the reliability and reproducibility of leakage results, the parameters the revised evaluation was carried out for three products with actual leakage history, and it was confirmed the leaks could be reproduced whereas the existing methods could not. To quantitatively verify the reproducibility, the filler content of the leaked samples was derived and the maximum filler content was 64% lower than that of the normal sample. The same results was found with the samples from the actual leakage site, thus verifying the reliability of the revised evaluation method.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.4
• /
• pp.297-303
• /
• 2018

With the changing trend of the building construction to high rising and large scaling, the underground structure has been increased, and its usage also increased and variety. Hence, to protect the underground structure against underground water, various water proofing methods has been developed. Among the many water proofing methods, the combined water proofing method using both asphalt seal and sheet has been widely used to secure the sufficient performance and decrease the construction failure. However, during the summer period of extremely high temperature conditions, the asphalt sealing materials were separated and leaked into the structure. Therefore, the aim of the research is to provide the quality standard of asphalt sealing material based on the various temperature changes depending on seasons. According to the experimental results, the temperature of the sealing materials applied on the slab was increased up to $54^{\circ}C$ which was $3^{\circ}C$ higher than the structure temperature of $51^{\circ}C$. Based on the melting test for asphalt sealing materials applied on the outside wall of the structure, in the case of water-dispersing typed materials showed significant melting down due to its slow evaporation and low viscosity. Furthermore, from the accelerated test conducted indoor conditions, a solvent-type and water-dispersing typed materials showed significant melting down due to their low viscosity and melting point in ambient conditions. Based on these results, viscosity and melting point are found as the important factors on asphalt sealing materials' quality, and it is necessary to designate the quantitative level of the viscosity and melting point for quality control.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.6
• /
• pp.50-58
• /
• 2020

When the concrete surface layer is damaged, The method of impregnating the concrete surface with a water repellent cannot secure the expected durability. Recently, various waterproofing and water-repellent materials were mixed into concrete or mortar to secure water repellency even inside cracks, but compressive strength was greatly reduced. In order to overcome the decrease in compressive strength, there has not yet been a study using the merits of organic and inorganic materials at the same time, so in this study, the physical properties and water repellency performance were evaluated by mixing an organic/inorganic composite water repellent appropriately mixed with an organic and inorganic material into the mortar. When mixed with organic/inorganic water repellent, the flow and air content were reduced by about 10% and 50% compared to the Liquid specimen. In the case of the P6L1 specimen, it was confirmed that the compressive strength decreased by about 3.5% compared to the non-mixed mortar at 39.5 MPa, the same as the existing water repellent, Powder. Water-repellent performance The organic-inorganic composite water repellent mixture specimen confirmed higher water repellency than the existing water repellent mixture powder, and the chloride penetration resistance evaluation result showed that the organic-inorganic composite water repellent mixture specimen reduced the passing charge by about 45% compared to the non-mixed mortar. In summary, it is judged that the P5L1 organic/inorganic composite water repellent mixed with a powder water repellent and a liquid water repellent in a ratio of 5:1 is the most reasonable to prevent the decrease in compressive strength and secure water repellency.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.468-477
• /
• 2019

This study analyzed the major contents and results of revision through an analysis of the specifications and the field survey to revise the construction cost calculation criteria. The result of the survey found that the background processing difficulty was reduced due to an improvement of the quality level of the field floor, and the enhancement of the material's function brought a decrease in construction time and the application of various construction methods. In addition, the application of combined waterproofing methods using more than one material was increasing and the productivity differed according to the site and location. Based on these results, waterproof items were subdivided and applied to the composite construction method, and the input items were differentiated according to the material and construction method. The adequacy of the construction calculation criteria was ensured by presenting the criteria classified according to the construction area, and deleting the items that are not applicable and amending them to make them suitable for the specifications by reflecting the actual conditions of the construction on the site.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.2
• /
• pp.8-16
• /
• 2023

This study evaluated a shear capacity of confined socket-bolt (CSB) shear connector developed for utilizing cast in placed pile (CIP) as a permanent underground wall. The push-out tests were performed in the specimens with different CIP types, CSB shear connector types, L/d, and concrete compressive strengths of concrete pile, and with or without waterproofing at interfaces between CIP and underground wall. Test results showed that the specimens with a H-shaped pile were fractured in the CSB shear connector, while the fracture concentrated in the concrete part of the specimens with a reinforced concrete pile was alleviated as the compressive strength of the concrete pile increased, resulting in the severe fracture of CSB shear connector. The maximum shear capacities of the specimens with high strength bolts and reinforcing bars used as CSB shear connector were approximately 1.22 and 1.20 times higher than those of the specimens with a H-shaped pile, respectively, and 1.10 and 1.16 times higher than those of the specimens with a reinforced concrete pile, respectively. Meanwhile, the maximum shear capacity was not significantly affected by the embedding length of the CSB shear connector and overlapping length of reinforcing bar. The predicted shear capacities calculated from the KDS standards were lower than the measured values of all specimens tested in this study.