• Title/Summary/Keyword: 시공줄눈

Search Result 41, Processing Time 0.031 seconds

An experimental evaluation for improving resistance against freezing-thawing of concrete (콘크리트 동결융해 저항성 향상을 위한 실험적 평가)

  • Lee, Sang-Hyun;Kim, Kwang-Ki;Yoo, Jae-Yong;Lee, Joo-Ho;Ryu, Hwa-Sung
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.11a
    • /
    • pp.151-152
    • /
    • 2015
  • Concrete parking slab is often deteriorated severely after winter season because of concrete's freezing and thawing phenomenon. In this study, some methods to improve resistance against freezing-thawing is experimentally tested.: 1) concrete strength, 2) air content in concrete, 3) saw-cut effect and finish material. After experiment, in case of no finishes, 24MPa concrete with 4% air content is tested best result in terms of relative elastics modulus among testes ones. In case of concrete with finishes, all specimens are improved regardless of finishes compared to concrete with no finishes. Improvement degree compared to no finish is as follows : Polyurea > Resin-mortar > hardener and the number of improvement degree is 5, 4, 2% respectively. Further work is required considering construction site condition such as gaining water on surface and remicon in order to reflect site condition.

  • PDF

Prism Compressive Strength of Non-structural Concrete Brick Masonry Walls According to Workmanship (시공정밀도에 따른 비구조용 콘크리트벽돌 조적벽체의 프리즘 압축강도)

  • Shin, Dong-Hyeon;Kim, Hyung-Joon
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.36 no.2
    • /
    • pp.127-136
    • /
    • 2020
  • Prism compressive strength is the most influential parameter to evaluate the seismic performance of non-structural concrete brick masonry walls, and is affected by the practice and workmanship of masonry workers. This study experimentally investigates the influence of workmanship on prism compressive strength throughout the compressive test with prism specimens constructed according to masonry workmanship. To do this, the workmanship is categorized into good, fair, and poor conditions which are statistically evaluated with thickness and indentation depth of bed-joints. Then, the effect of workmanship on the structural properties of masonry prisms is evaluated by investigating relations between properties such as their compressive strength, elastic modulus and numerical parameters such as thickness, filling of bed-joints. This study demonstrates that the indentation depth is more important parameter for structural properties of masonry prisms and masonry prisms with loss in bed-joint area less than of 7% can be in fair condition.

Early-Age Behavior Monitoring of Bus-Stop-Section Pavement Constructed Employing Precast Concrete Pavement Method (조립식포장 공법을 적용한 버스정거장 포장 초기 거동 추적조사)

  • Oh, Han-Jin;Kim, Seong-Min;Hwang, Ju-Hwan;Park, Won-Joo
    • International Journal of Highway Engineering
    • /
    • v.13 no.1
    • /
    • pp.229-237
    • /
    • 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.

Development of Tie-Bar Installation Method for Concrete Pavement Widening (콘크리트포장 확장부 타이바 설치방법의 개발)

  • Hwang In-Kyu;Yang Sung-Chul;Jeong Jin-Hoon;Yoo Tae-Seok
    • International Journal of Highway Engineering
    • /
    • v.8 no.1 s.27
    • /
    • pp.33-43
    • /
    • 2006
  • Pull-out strength of tie-bin used in pavement construction is not an issue because those are embedded in newly placed concrete slabs. However, sufficient pull-out strength should be secured in widening constructions because, in case, the tie-bars are inserted into drilled holes of the existing slabs with liquid filler. Insufficient pull-out strength will result in lowered load transfer efficiency between adjacent slabs in addition to poor serviceability and durability due to joint widening. The pull-out strength of the tie-bars installed by current method is evaluated and improved methods are proposed. The field pull-out strength obtained by the current method was only 42.7% of required strength. Its first counterproposal is using to insert the liquid filler into drilled holes and stoppers to prevent it from flowing out of the holes. However, this method was not judged to secure desired level of quality control. The second counterproposal which substitutes the existing type of the tie-bars by SL anchor bolts was judged to secure sufficient pull out-strength in addition to the quality control and constructibility.

  • PDF

Construction Methodology for Chum-Sung-Dae Validation through the Present Configuration (첨성대 건립에 대한 시공방법론 첨성대의 얼개를 통한 논증)

  • Kim, Jang Hoon;Park, Sang Hun
    • Korean Journal of Heritage: History & Science
    • /
    • v.42 no.2
    • /
    • pp.40-61
    • /
    • 2009
  • A new construction methodology has been proposed on a scientific basis to reason a rational explanation for the structure and the present configuration of Chum-Sung-Dae. This is because there is no way to otherwise explain the gap between our expectation that the people in Shilla are assumed to be and the problems, such as the use of a temporary supporting structure including falsework, the use of a conveying device for stonework and the practice of soil fill, raised when the construction method in nowadays is applied to the structure. Furthermore, it is because the questions, such as the difference of an azimuth angle between the southward opening and the square podium, the skewed circular plan in layers of the body, misalignment between neighboring layers of the body, disagreement between the inclination due to slight sidesway and the eccentricity in each layer of the circular body, perfectly aligned vertical and horizontal joints and the existence of soil fill, raised from the present configuration of Chum-Sung-Dae, also require a reasonable explanation based on scientific evidences, if any. Therefore, the proposed new construction methodology, in which the soil hill outside as well as the soil fill inside the Chum-Sung-Dae may have been utilized as a temporary scaffolding system for construction, is the highly probable one that the builders of Chum-Sung-Dae might have inevitably employed. The existence of great tombs, scattered in Hwang-Nam-Dong close to Chum-Sung-Dae, implies that the people of Shilla might have accepted the proposed new construction methodology as a natural one.

Joint Stiffness Tests for Precast Concrete Pavement (프리캐스트 콘크리트 포장의 하중전달 성능 실험)

  • Yang, Sung-Chul;Kim, Seong-Min;Yoo, Tae-Seok;Han, Seung-Hwan
    • International Journal of Highway Engineering
    • /
    • v.10 no.2
    • /
    • pp.229-239
    • /
    • 2008
  • This paper compares the load transfer efficiency between precast concrete pavement specimen and typical concrete pavement specimen by means of laboratory and field tests. An experimental method was developed to evaluate the load transfer efficiency of the dowel bars buried in the concrete pocket and grouted with cement mortar. The test results showed that the load transfer efficiency of the specimen for the dowel bars repaired with grout was equivalent to that of the control specimen. In addition, a series of FWD field tests were conducted on the precast pavement to evaluate the joint stiffness. The field test results revealed that the central deflection of the precast slab slightly increased but the load transfer efficiencies at the joints were almost the same as those in the typical concrete pavement slab.

  • PDF

Leakage Situation and Main Leakage Areas of Domestic Residential Building Underground Parking Lots (국내 공동주택 지하주차장의 누수 실태 및 주요 누수 부위 조사)

  • Lee, Jung-Hun;Song, Je-Young;Oh, Sang-Keun
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.4 no.4
    • /
    • pp.496-503
    • /
    • 2016
  • This paper studies the leakage situation of domestic residential building underground parking lots and main leakage areas. 18 complexes were studied and the results showed that 80% of buildings with exterior waterproofing had no leakage, but all buildings with interior waterproofing had leakage. According to a survey among professionals, water leakage problems are considered to be severe in underground parking lots and a preventative measure is required by the government. By comparing the survey and the actual situation at hand, the results showed that the lowest floor slab, wall construction joints, and floor expansion joints were the most prone to leakage. Based on the results, further study to develop a design manual for the appropriate prevention of leakage is deemed necessary.

Analysis of the Finishing Failure in the Railway Station Platform and Deduction of Improvement Plans (철도역사 승강장 연단부 마감 탈락에 대한 원인 분석 및 개선 방안)

  • Ko, Sewon;Yu, Youngsu;Koo, Bonsang;Kim, Jihwan
    • Korean Journal of Construction Engineering and Management
    • /
    • v.23 no.1
    • /
    • pp.46-53
    • /
    • 2022
  • The railway platform is an important facility closely related to the safety of passengers, trains, and images of railway facilities, and requires thorough facility management. However, the problem that the finishing material (plastering mortar) for the joint finishing of dissimilar materials (concrete+granite) falls off in the direction of the track at the platform podium is occurring multiple times across the country. Since these problems threaten the safety of train operation and the safety of passengers, immediate and continuous management is required. This study tried to derive improvement plans through the analysis of the drop-off problem of finishing materials occurring at the platform podium. The status of missing finishing materials for the platform podiums of about 200 railway stations and the related design and construction standards of the Korea National Railway were investigated. After that, the cause of the drop-off of the finishing material was analyzed, and as a result, it was found that the main cause was the boundary between the roadbed and the architectural process that occurred during construction. Subsequently, in connection with the derived causes and design, construction standards, (1) improvement of finishing materials or construction methods, (2) design of finishing materials that are easy to adjust height, (3) design of separate finishing methods, (4) improvement methods and durability were suggested.

A Study on a Runoff Coefficient of Block Paved Area with Considering Regional Rainfall Distribution (지역별 강우분포를 고려한 블록포장지역의 유출계수 산정에 관한 연구)

  • Kang, Shin-Kweon;Kim, Tae-Gyun
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.36 no.4
    • /
    • pp.111-119
    • /
    • 2008
  • The runoff coefficient for a block paved area is determined with regional rainfall distribution. The Rational Method is a basic equation of a drainage system design and is a function of runoff coefficient, rainfall intensity and area. A runoff coefficient is the ratio of rainfall intensity and runoff. The rainfall intensity which is a function of the return period and rainfall duration differs by region. Therefore the runoff coefficient varies regionally even though there is the same return period and rainfall duration. The ratio of rainfall intensity and rainfall duration is decided by the loss of rainfall. The constant infiltration capacity of Horton's equation is adopted to determine the loss of rainfall. As time passed, the joint of the block paved area through which the infiltration occurs is covered by pollution material, sandy dust, pollen and is hardened by foot pressure, so the constant infiltration capacity may decrease. Six different sites were selected to verify the assumption of the constant infiltration capacity decrease and 10 year return period. 10, 20, and 30 minute rainfall duration were applied to calculate rainfall intensity. The results indicate that the Horton's constant infiltration capacity decreases over time and the minimum constant infiltration capacity is selected to compute runoff coefficients. The runoff coefficients varied by region ranging from $0.94{\sim}0.84$ for 10 minute of rainfall duration.

Development of Roughness-Model for Jointed Plain Concrete Pavements in Express Highway (고속도로 줄눈 콘크리트 포장의 평탄성 모델 개발)

  • Park, Young-Hoon;Chon, Beom-Jun;Kim, Young-Kyu;Lee, Seung-Woo
    • International Journal of Highway Engineering
    • /
    • v.12 no.2
    • /
    • pp.9-16
    • /
    • 2010
  • Roughness is the most important factor to maintain the road performance, and affects greatly on the design life in Jointed Plain Concrete pavements. Also, the factors the evaluate pavement‘s commonality is the three method such as functionality, safety and structural performance. In evaluating function of road, representative factors is the roughness, which has been used to determine maintenance time as key standard. As research for roughness is absence in pavement design. Applied roughness-model had a low-reliability in Korea. Therefore, it is needed to develop reliable model in road roughness. In this research, uniform specific is applied to distribute them after selecting the concrete pavements. Concrete pavement is divided by sections of 238. Total length of this sections has 281km and account for 16% of total road length in korean concrete pavements for selected sections. Considering the korean roughness-model, the evaluation of roughness is performed for the freezing index, average annual rainfall, condition for the base, the amount of traffic as well as spalling(%), cracking(%), age(year) at the selected section at the selected section. Also, additional sections is selected to evaluate various age which affects on the roughness. As a result of the analysis, it showed that spalling(%), cracking(%), age(year), and the condition of the base affected road roughness. When the correlation with the road roughness was analyzed, the reliable model for road roughness was proposed, and the ratio that can explain road roughness was R2-68.8% and P value-0 which is statistically meaningful.