• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.9
• /
• pp.928-934
• /
• 2009

Underwater impulsive sound such as underwater blasting noise, piling noise and stone breaking hammer affects marine animal hearing response and organs. This study describes the characteristics of various impulsive noise from waterfront construction site and their effect on fish. Time constant, peak pressure, energy and SEL(sound exposure level) of four different underwater impulsive sounds are quantified. Auditory and non-auditory tissue damage ranges are derived by comparing their quantities to the exposure criteria for fish. Damage ranges of auditory tissue and non-auditory tissue of underwater boring blast of 150 kg of charge, are about 100 m and 300 m, respectively. Other three impulsive sounds also gives damage effects but less than that of underwater boring blast.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.10a
• /
• pp.308-315
• /
• 1996

The utilization of high flowing concrete in construction sites is a world wide trend, and it will be increase to need for high flowing concrete in our construction sites. While it is quite easy to make high-flowing concrete in the laboratory, controlling slump in the field long enough to ensure easy placement once the concrete arrives at job site can be difficult. This study is the experimental study on the high-flowing and engineering properties of high flowing concrete using river sand and crushed stone according to the replacement percentage of fly-ash. As a results of this study is the mix proportion of replacement percentage of fly-ash 30% better than the others. And it is confirm to possibility of manufacture of the high flowing concrete.

• Journal of architectural history
• /
• v.29 no.2
• /
• pp.19-30
• /
• 2020

In the early of Joseon Dynasty, Royal Tomb developed from stone chamber tomb to lime chamber tomb through precedents. The lime chamber tomb consists of main-chamber(JeongGwang) and sub-chamber(ToeGwang). This separation makes character to construct tumulus of the Royal Tomb half and half. By this character, the Royal Tomb are not constructed by separate structure but constructed by coadjustment. The underground structure and tumulus of the Royal Tomb affect each other in the size and method of construction. The selecting type of Royal Tomb is generally made decision through terrain and politics. This study prove the architectural structure is also one of the major cause the that select type of Royal Tomb.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.65-67
• /
• 2011

This research analyzed the mechanical properties of high strength concrete produced by limestone aggregate, and summarized the result as follows: Due to the property of unhardened concrete, slump flow value increased more or less according to the increase in LG replacement, but didn't show a big difference while clear tendency of air content couldn't be found. Due to the property of hardened concrete, there appeared an increase in the rate of compressive strength the more LG replacement increased, and the modulus of elasticity also showed a tendency similar to the increase rate of compressive strength.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.61-62
• /
• 2021

Exterior wall molding, which is widely applied as a design element of the exterior wall of domestic apartment, should be applied as a nonflammable or semi-nonflammable material grade according to the rules on standards for evacuation/fire protection structures of buildings. For this reason, stone and AL sheet are mainly used, but stone is expensive and design autonomy is low. Inorganic reinforced CLC nonflammable molding was applied to the exterior wall of the building through tests of nonflammable performance, noise reduction, and installation stability.

• Journal of architectural history
• /
• v.15 no.2
• /
• pp.77-94
• /
• 2006

"Mixed construction of platform" means the platform which was constructed by mixing heterogeneous materials such as roof tiles or bricks with divided stone of trimmed stone. This kind of construction technique was not known or found from the building sites of Goguryo or Silla so far and therefore it used to be understood as a unique platform construction technique or the product of technology and creativeness of Baikje's craftsman. The mixed construction of platform of Baikje came to position itself as one of the patterns of platform mainly used over Sabi period and we found the pattern from the sites including Imryugak site in Gongju, temple for royal tomb in Gwanbuk-ri, Wangheungsa Temple site, building site in Keumseong Mountain, Ohapsa Temple site in Byryeong. From the fact that they used a variety of materials which they could easily get around them such as roof tiles or bricks in addition to stones for the construction of platforms, we can see the feasibility and decoration characteristics of their material supply at that time. On the other hand, this mixed construction of platform was not popular in Goguryo and Silla, the major reason for which is judged to be non-existence of platforms to construct using bricks or roof tiles which could be constructed together with platform using divided stones. This is supported by the results of excavation of Hwangryongsa Temple site, Bunhwangsa Temple site, Heungryunsa Temple site of Silla which gave us comparatively abundant excavation data, and Jeongreungsa Temple site, Cheongamsa Temple site, Toseongrisa Temple site and building site in Daeseong Mountain castle and Anhak Palace site of Goguryo. For further progressive study on the mixed construction of platform of Baikje in the future, we will have to review more on the social background and technical background with the linkage with archeology and architecture at that time which led to the creation of such platform.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.11a
• /
• pp.19-22
• /
• 2007

This study discussed the prevention of the spalling and improvement of the fire resistance performance how to fill up lightweight foamed concrete on high strength RC column attached with the stone panel. The destructive spalling extremely occur caused by sudden high temperature and increased vapor pressure corresponding to falling the ston panel at all RC column, and the steel bar is exposed. The stone panel fall off about 30 minutes and spalling occur about 70 minutes on Plan RC column, fire endurance paint, and fire endurance mortar, so it can be confirmed that fire endurance paint and mortar, which is used as fire endurance material, are not effective. In the other side, it can be protected from fire about $120{\sim}140$ minutes when the lightweight foamed concrete is used as fire endurance material. For the weight loss after the fire test, plain is 33, fire endurance paint is 37%, and fire endurance mortar s 40.7%. And W/B 60%-3 is 53.4%, 60%-1.5 is 40.1%,65%-3 is 39.4%, and 65%-1.5% is 47.1. Overall, the weight loss of the plain is lower than that of the lightweight foamed concrete.

• Industry Promotion Research
• /
• v.5 no.2
• /
• pp.27-32
• /
• 2020

This study is a study on the size of the stone statues of the royal tombs in the Joseon Dynasty. In summary, the size of the stone statues of Moon, Inseok and Unmanned Stone increased in the 1600s and then decreased slightly in the 1700s, but increased in size in the 1800s. It was confirmed that the average analysis result. The statue of Seok-in of the Royal Tombs of the Joseon Dynasty reflects the characters of the time, and through this, the typical figures of the times can be examined. The royal tomb has consistency and uniqueness, and the norms regarding the size of stone statues have changed over time. As a building of the authoritative symbol of the ruling class, it was a national construction where royal tombs were built according to rituals and laws. It is said that the size of the stone statues in the Joseon Dynasty was about 90cm smaller than the stone statues of the tombs. In this study, the significance of this study is to confirm the stone size of each stone age in the royal tomb of Joseon.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.3
• /
• pp.118-125
• /
• 2011

The size and distribution of concrete void was one among the factor determining durability of concrete. Recently, there was a lot of researches related to the High-Fludity Concrete(HFC) with field applications. However, the research about the void structure having an effect on durability of concrete is insufficient. Therefore, in this research, Conventional Concrete(CC) and HFC using lime stone powder and fly-ash of 30 MPa range was manufactured and observed the void structure of CC and HFC. Experimental results showed that average pore diameter in the case of the 30 MPa range HFC was to be lower than CC and SEM analyzed result, HFC was firmer inner structure than CC.

• Journal of the Korean Geosynthetics Society
• /
• v.13 no.3
• /
• pp.31-38
• /
• 2014

The geogrid encased stone column (GESC) system, which increases the confinement effect, has been developed to improve the load carrying capacity of stone columns. The resonable design method for calculating the geogrid ring tension force and ultimate bearing capacity that can be applied to the design of GESC is proposed. In order to calculate design procedure for GESC, two ultimate bearing capacities were compared. One is the ultimate bearing capacity measured using data of the field loading test in light railway site and the other is the ultimate bearing capacity using suggested design procedure of GESC. The results indicated that design method of GESC higher ultimate bearing capacities compared with field loading test.