• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.787-790
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• 2012

In downtown, construction noise related claims are the most important issues. Sometimes noise related claims halt the construction process. Therefore, Introduction of noise reduction measures is common to construction process with a loud noise. This case is about concrete pouring for mat foundation of super tall building. Concrete pouring process using High Pressure Pumping machine causes high noise level in the vicinity of area. And large number of transit-mixer truck cause traffic congestion. This paper introduces effort and process to prevention of construction noise claims on massive scale concrete pouring.

• 한국건설순환자원학회논문집
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• 제12권3호
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• pp.298-305
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• 2024

본 논문은 철근콘크리트 슬래브의 바닥 충격음을 개선하기 위한 기초연구이다. 시공에 의해 두께의 차이가 발생하는 경우를 고려하여 철근콘크리트 슬래브의 단면을 모르타르로 회복시켰을 경우 차음 특성의 변화를 분석 하였다. 분석 대상 주택은 평면형식이 다른 84 type와 59 type의 2종류로 하였으며, 철근콘크리트 슬래브 위에 단면을 회복하기 위해 중량모르타르로 단면 회복용 모르타르 시공할 때를 철근콘크리트 슬래브 단독과 일반 모르타르로 단면 회복용 모르타르 시공한 경우와 비교하여 진동가속도레벨과 음압의 차이를 측정하였다. 모르타르를 타설 후 슬래브에 대해 진동가속도 레벨을 측정한 결과, 84 type 63 Hz에서 CS 모르타르가 66.4 dB, ES 모르타르가 66.1 dB로 일반 모르타르에 비해 2 dB 이상 낮게 나타났다. 또한 철근콘크리트 슬래브 단독과 비교할 때 CS 모르타르가 5.5 dB, ES 모르타르가 4.6 dB이 저감되어 비교적 우수한 값을 보였다. 바닥충격음 음압은 결과의 경우, 84B type이 63 Hz에서 CS 모르타르와 일반 모르타르가 67.3 dB로 유사하게 나타났으며, 철근콘크리트 슬래브 단독 대비 저 감량은 CS 모르타르가 3.6 dB, ES 모르타르가 2.7 dB, 일반 모르타르가 1.4 dB 저감되었다. 철근콘크리트 슬래브의 두께를 보상하기 위하여 모르타르를 타설함으로서 진동가속도레벨 및 바닥충격음은 감소하였으며, 동제련 슬래그 잔골재를 사용한 중량모르타르를 사용할 경우 상대적으로 우수한 성능을 발현하는 것으로 나타났다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.808-813
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• 2009

Top-down method is widely used for urban area construction for its advantages in reducing environmental problems such as dust and noise, and saving construction cost depending on given conditions of a construction site. Because the excavation and construction of super- and sub-structures of the building have to be proceeded simultaneously, a column has to be embedded prior to excavation. This column is called a pillar column or pre-founded column. Usually a wide flange section is used for these columns. To place the columns, usually the diameter of casing holes needs to be larger than the section of the wide flange itself in order to accommodate a couple of tremie pipes for pouring concrete. In this paper, a newly developed method of using circular pipe as an alternative to the existing wide flange section is discussed. The crucial part of the new method is to develop a connection between the circular column and concrete flat slabs. For shear force transfer from concrete slab to the concrete filled tube (CFT) column, shear jackets with studs and shear bands are proposed. The studs are welded on the jackets at shop and placed around the circular column on site. The shear bands are welded on the outer side of the CFT at shop and inserted into ground with the CFT. Test results and application of the method to a construction site are also provided in this paper.

• 한국세라믹학회지
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• 제44권9호
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• pp.529-535
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• 2007

Calcium oxide has been used as a demolition agent in fracturing rocks and old concrete structures, etc. With the agent, demolition work can be done in safety without a noise, vibration and any other pollution, since high expansive pressure is obtained gradually by only mixing the agents with water and pouring the slurry into boreholes. But application of the non-explosive demolition agent is a time-consuming job, especially in winter. Essentially, this problem is related to the reaction rate of calcium oxide with water. This study examines the influence of additives such as cement and anhydrite on expansion pressure of calcium oxide at different curing temperatures. The expansion pressure of calcium oxide began to increase steadily with the rise of the curing temperature. When mixing calcium oxide alone with water, blown-out shot occurred. But as additives were added to calcium oxide, the reaction of calcium oxide delayed and the expansion pressure showed gradual increment. Especially, anhydrite showed a superior delaying effect than cement on the reaction of calcium oxide.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.89-98
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• 2017

The floor heating method generally uses a wet construction method including the installation of resilient material, lightweight foam concrete, heating piping, and finishing mortar. Such a wet construction method not only delays other internal finishing processes during curing period for two mortar pouring process, but also has a disadvantage that it is difficult to replace the floor heating layer when it deteriorated because it is integrated with the frame. Dry floor heating construction method can be a good alternative in that it can solve these defects. Conversely, when it applied to the wall structure that is vulnerable to the interlayer noise compared with the column-beam structure, the question about the heavy-impact sound(HIS) insulation performance is raised. Therefore, conventional dry floor heating method is hard to apply to the wall structure apartments. Therefore, for the purpose to improve the applicability of dry floor heating method in wall structure apartments, this study investigated the change of floor impact sound, especially HIS insulation performance which is one of the required performance for the floor structure. This study tried to examine whether the change of heavy-impact sound pressure level(SPL) shows a tendency at the significant level according to the shape and mass of the floor structure. Through filed experiments on wall structure apartment, this study confirmed that the form of the raised floor shows better HIS insulation performance than the fully-supported form. In addition, it was also confirmed that the HIS insulation performance increases with the mass on the upper part. Moreover, this study found the fact that a mass of about 30 kg/m² or more should be placed on the upper structure to reduce the heavy-impact SPL according to the bang machine measuring method. Although this study has a limit due to insufficient experiment samples, if the accuracy of this study is increased, it will contribute to the diffusion of dry floor heating by setting the HIS insulation performance target and designing the dry floor heating structure that meets the target.