• Title, Summary, Keyword: Slip Form

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Setting Time and Strength of Slip-form Method Applied Caisson in Low-temperature Period (슬립폼공법 적용된 동절기 케이슨의 온도에 따른 응결시간 및 압축강도)

  • Kim, Bong-Joo;Kim, Jae-Hun;Kim, Chan-Soo;Jo, Ho-Kyoo
    • Journal of Korean Society of Hazard Mitigation
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    • v.6 no.1
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    • pp.1-7
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    • 2006
  • In the harbor construction work, caisson is made by slip-form method and curing temperature of caisson concrete need heating in the low-temperature. To get the setting time and compression strength of slip-form method applied caisson at various curing temperature. The curing temperature is divided to the temperature of slip-form and the temperature of second curing curtain. In consideration of setting time, compression strength of concrete and form-removal time, the best temperature is $25^{\circ}C$ at 6 hours slip-form curing time.

A Study on the Determination of Setting Time of Concrete in the Determination of Slip-up Speed for Slip-Form System (슬립폼 시스템 상승속도 결정에 요구되는 콘크리트에서의 초기경화시간 결정을 위한 연구)

  • Kim, Heeseok;Kim, Young-Jin;Chin, Won-Jong
    • Journal of The Korean Society of Civil Engineers
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    • v.31 no.4A
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    • pp.295-302
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    • 2011
  • The setting time which is the important element for the determination of slip-up speed of Slip-Form system is the hardening time of early-age concrete when the in place concrete has minimum compressive strength before the concrete appears out of Slip-Form system. But it is very difficult to predict the setting time because it depends on not only the composition ratio of concrete but also various conditions of construction fields. Thus, the technique to estimate accurately and continuously the hardening time of early-age in place concrete during operating Slip-Form system is necessary to guarantee the safety of Slip-Form system and the maintenance of the shape of concrete. Ultrasonic wave-based nondestructive testing methods have the advantages which are accurate and continuous in estimating concrete compressive strength. Of such methods, the method using surface wave which propagates along the surface of material is effective for thick member such as a pylon. Thus, in this paper a study on the determination of slip-up speed for Slip-Form system using surface wave velocity is performed. The relation between the slip-up speed of Slip-Form system and the setting time is formulated, and the surface wave velocity is estimated from continuous wavelet transform of the numerical results for surface wave propagation. Finally, the accuracy of this method according to the distance between the wave source and receivers and the relation between the estimated surface wave velocity and the elastic modulus are investigated.

A Study on the Determination of Slip-up Time for Slip-Form System using Surface Wave Velocity (표면파 속도를 이용한 슬립폼 시스템 상승 시기 결정에 관한 연구)

  • Kim, Heeseok;Kim, Young Jin;Chin, Won Jong;Yoon, Hyejin
    • Journal of The Korean Society of Civil Engineers
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    • v.32 no.5D
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    • pp.483-492
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    • 2012
  • The early setting time of concrete is an important factor determining the slip up velocity of the slip-form system. Accordingly, need is for a technique evaluating the early setting time in order to secure the safety of the slip-form system and the construction quality of concrete. This paper intends to estimate the early setting time by evaluating the setting degree of concrete using surface wave velocity so as to determine the slip up time of the slip-form system. Penetration resistance test and compressive strength test are performed first to clarify the relationship between the early setting time of concrete and the compressive strength. Then, compressive strength test and ultrasonic wave test are conducted to examine the relation between the compressive strength and the surface wave velocity. Continuous wavelet transform is adopted to measure the surface wave velocity. Numerical analysis is carried out to demonstrate the appropriateness of the application of continuous wavelet transform. Based on these results, the propagation velocity of the surface wave required for the slip up of slip-form system is suggested. Finally, a reduced model test of the slip-form system is conducted to verify the feasibility of the proposed surface wave velocity for the determination of th slip up velocity.

A study on the slip-up speed of a shaft using heating slip form (히팅슬립폼을 적용한 수직구 구조물의 상승속도에 관한 연구)

  • Ko, Eomsik;Lee, Sanghun;Park, Jongpil;Zi, Goangseup;Kim, Changyong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.6
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    • pp.811-823
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    • 2019
  • Slip form method is applied to many cases of a shaft these days because it is safer, more economical and faster than cast-in-place method. Slip-up height of the method is approximately 2.5 to 4.0 m/day. If the temperature of concrete is outside the range of 10 to 30℃, the effects of changes in strength or elastic characteristics are significant. Therefore, it is difficult for slip-up speed to be higher than 3 m/day during winter construction. In addition, concrete has heat caused by hydration, which causes temperature cracking of hardened concrete. Therefore, temperature control of concrete curing is necessary for the continuous slip-up of slip form. In this study, the rebound hardness, time of ultrasonic waves propagation, heat of hydration, and external temperature are measured by developing heating panels and test devices for the continuous slip-up. Based on this, heating slip form is manufactured; this was applied to "Kimpo sites" and "Sinwol sites". The compared slip-up speed samples were 1.9 m/day or 0.200 m/hr on average at Gimpo sites (08:00~17:30) and 2.0 m/day or 0.210 m/hr at Sinwol sites.

An Experimental Study on Early Strength Development of High-Strength Concrete to Apply Slip-Form (슬립폼 적용을 위한 고강도콘크리트의 조기강도 발현성상에 관한 실험적 연구)

  • 주지현;여동구;강석표;길배수;남재현;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.355-358
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    • 2000
  • Nowadays, with high-storied and large-sized of structures, high-strength concrete is applied to the various kinds of concrete structure. Among of them, for reduction of completion time, high-strength concrete is applied to the high-storied tower, building which is constructed continuously by the slip-form method and it is expected to be on the increase. In this case, it is very important to grasp development of early-strength to apply the slip-form method. But the strength data prior 1 day is rare. Therefore, to apply slip-form method in field, this study aim is to present basic data for development of early-strength of high-strength concrete, through examining development of strength by different curing temperature, replacement of fly-ash.

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Structural Behavior of Wall-Type Structure with the Application of Slip-Form System (슬립폼 공법으로 건설된 벽식 구조의 거동에 관한 연구)

  • 문정호;이리형
    • Magazine of the Korea Concrete Institute
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    • v.7 no.4
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    • pp.157-168
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    • 1995
  • The structural performance of Slip-Form system was examined to make use of many advantages of fast construction and high quality c0ncret.e. However, the separate cor~struction of wall and slabs may cause some weaknesses around the wall-slab connection region. Thus, the purpose of the study is to examine the structural performance of wall-type structure constructed by Slip-Form method and to develop an efficient connection system between wall and slabs. In order to investigate the system, 7 wall specimens and 8 wall-slab joint specimens were tested and the experimental results were compared with the design equations and theoretical analysis. A satisfactory performance was obtained from the wall specimen tests. However, wall-slab joint specimens with rebar connection materials I Ilalfen] were shown that. the strength of' wall should be checked during design porocess.

A Study on the Section Change Using the Slip-Form Method (슬립폼 공법 적용 시 단면변화에 대한 고찰)

  • Suh, Jin-Sun;Han, Jun-Young;Im, Chil-Soon
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • pp.123-128
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    • 2007
  • Already, core wall construction method for apartment wall structure and general building special areas applied the engineering method's appropriate examination. Also, trial and error depending on slip-form method is a good examination opportunity to consider. In the present paper's slip-form engineering method l)Casting concrete to slab in sliding 2)RC structure + SRC structure (part of segment) 3)Inside segment variation(straight line-diagonal-circle) are together while determining whether it is possible not to carry out actual construction work on the structure. Finally, small problems continuously appear on actual slip-form method application, design and engineering, starting with planning thoroughly the field examination and diagnosing the atmosphere, minimizing cost, secure work safety facilities characterized by good quality, slip-form research extension, development and decision-making.

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The basic study of the detail development of the Wall-type APT joint using Slip Form and Deck plate. (Slip Form과 Deck Plate를 채용한 벽식 APT의 접합부 Detail개발의 기초적 연구)

  • Lee, Hee-Doo;Park, Shin;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.127-132
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    • 2003
  • The purpose of current study is about how to construct wall-type APT in slip form and Deck plate applied different connection of materials that wall and slab. A proposal construct's solution is using the continuous a binding string that the main of contents are slab or stairs which horizon structure part construction is joined the vertical structure part, new we Proposed of 2 solution that new technology development. We'll suggest that the development is in the construct of higher stories APT more better other construction method. We expect that the new method is good but we have many things to solute themes. Thus, we decided that this development contents are needed that correct structural investigation and constructor's security of speciality and through a fact construct, correct verification.

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A Study on the Design of the Slip-Form System for the Construction of Tapered Concrete Pylons (변단면 콘크리트 주탑공사의 슬립폼 시스템 적용을 위한 설계기술 연구)

  • Yoon, Hyejin;Kim, Young Jin;Chin, Won Jong;Kim, Hee Seok
    • Korean Journal of Construction Engineering and Management
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    • v.15 no.3
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    • pp.128-135
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    • 2014
  • This paper studied design of slip form system considering the erection of a pylon mock-up. The height of the pylon is 10 m. A rectangular hollow cross-section was considered. The outer and inner dimensions of the pylons were varied with respect to the height. The thickness of 1 sides among the 4 faces were varied. Accordingly the slip form was designed to respond to continuous changes in its dimensions and thickness. Structural analysis was conducted to examine structural safety of the slip form. Virtual construction by BIM proved its practicality. The developed design technologies were successfully applied to the erection of a 10m high pylon executed for field verification test.

Numerical Study on Blockage and Slip Characteristics of Centrifugal Compressor Impellers (원심압축기 임펠러의 Blockage와 Slip 특성에 관한 수치연구)

  • Oh, Jongsik
    • 유체기계공업학회:학술대회논문집
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    • pp.236-244
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    • 2000
  • As the second part of the author's study, the aerodynamic blockage and the slip factor of 8 centrifugal compressor impellers are investigated, when the flow rate is changed from numerical stall to choke, using three-dimensional Navier-Stokes analysis results. Based on all the exit blockage distributions, an improved model equation with two adjusting coefficients is developed for the use in design processes with the agile engineering purpose. A popular expression of constant slip factors, the Wiesner's equation, cannot be applied in design processes when more accurate prediction is strongly required at design and off-design points. Slip factor variation is found to be also influenced by the blade loadings at midspan. When the flow rate is changed, a pattern of the slip factor variations is assumed to be a simple form which can be explained using midspan blade loading distributions.

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