학술논문
측압을 고려한 영구거푸집용 페로시멘트 프리패브-패널의 휨 실험 / Flexural Experiment of Ferrocement Prefab-Panel for Permanent Form Considering Lateral Pressure
Document Type
Dissertation/ Thesis
Author
Source
Subject
Language
Korean
Abstract
건설 현장에서 거푸집 공정은 기간이 많이 소요되며, 인력과 가설재가 과다하게 투입되는 복잡하고 위험한 공정이다. 또한 공사기간, 안전사고, 소음 및 진동, 환경보호, 그리고 비용적 측면에서 효율적이고 개선된 거푸집 공법이 요구되고 있다. 거푸집 작업 효율화의 최종 목표는 현장에서는 거푸집 조립과 탈형 작업을 제거하여 각종 가설재와 폐자재를 최소화할 수 있는 영구거푸집용 프리패브-패널을 개발하는 것이다. 한편, 전 세계적으로 다양한 분야에서 적용되고 있는 페로시멘트는 얇은 시멘트 모르타르 판으로써, 철망 등을 적층하여 보강한 단단하고 연성적인 구조물이다. 또한 철근콘크리트의 최초 발명품이기도 하다. 기존 P.C.(Precast Concrete)보다 무게가 가벼우면서도 안정적으로 타설 측압에 견딜 수 있다. 또한 연성능력, 방수성능, 내구성, 내화학성, 그리고 거주자와의 친숙함 같은 추가적인 장점이 있어 다른 어떤 재료와 견줄 수 없이 영구거푸집용 프리패브-패널에 적합하다. 이 연구에서 단위패널 실험을 통해 무수축 그라우트, 메탈라스, 용접철망을 구성재료로 한 페로시멘트 패널을 제작하였다. 그리고 공장에서 이 패널을 F-PSRC 기둥에 조립할 수 있는 여러 접합방식을 제안하였다. 단위패널의 휨 강도 실험 결과, 메쉬의 종방향 휨 성능이 가로방향 휨 성능보다 약 1.8배가 뛰어났다. 또한 단위패널 실험 결과, 실험 결과값이 이론적 해석값 보다 1.27~1.77배 큰 휨 강도를 보유하였다. 콘크리트를 타설하는 실물크기 실험 후 패널의 표면 상태를 확인한 결과, 균열이 양방향으로 발생되었다. 하지만 대부분 0.04mm보다 작은 폭의 균열들로 조사되었다. 육안으로 확인할 수 있는 변형은 발견되지 않았고 접합부의 밀림이나 탈락없이 측압에 대해 안전했다. 패널 표면의 변형률을 측정한 결과, 변형률 측정 평균값은 FEM 해석값의 0.57배로 나타났다. 그 이유는 설계기준에서 제시하는 산정식이 실제 측압보다 낮고, 패널의 두께 오차와 재료의 초과강도 때문인 것으로 판단된다. 단위 패널 실험과 실물크기 실험을 통한 역학적 분석 결과, Design Guide for Ferrocement(549.1R-18 2018)의 해석식은 보수적인 접근으로 거푸집용 패널에 적용 가능한 것으로 판단된다.
Formwork at construction sites is a complex and dangerous process that takes a long time and over-injects manpower and temporary materials. In addition, efficient and improved formwork is required in terms of the construction period, safety accident, noise and vibration, protection of the environment, and cost. The final goal of the formwork efficiency is to develop prefabrication-permanent forms that can minimize temporary materials and waste materials by eliminating form assembly and removal operations at the site. Ferrocement has the characteristics that best suit these needs. Ferrocement, which is widely applied in various fields around the world, is a thin cement mortar matrix plate, a hard, ductile structure that has been reinforced by layering mesh reinforcement. It is also the first work of reinforced concrete. Ferrocement is lighter in weight than the P.C. (Precast Concrete) member, but can reliably withstand the lateral pressure of concrete casting. In addition, ferrocement has additional advantages such as ductile capacity, waterproof performance, durability, chemical resistance, and familiarity with residents, making it suitable for permanent formwork systems, which cannot be compared with any other material. In this study, through the unit panel experiments, ferrocement panels with Hydraulic Cement Grout (Non-Shrink), metal lath, and welded steel wire were manufactured. Several joint arrangements have been proposed at the factory to allow this ferrocement panel to be assembled on F-PSRC columns. As a result of the experiments of unit panel flexural strength, the longitudinal flexural performance of the mesh was about 1.8 times better than the transverse flexural performance. In addition, as a result of the unit panel experiment, the results of the experiment have a flexural strength of 1.27 to 1.77 times greater than the theoretical forecast value. After concrete casting mock-up tests, the surface condition of the panel was checked and cracks were produced in both directions. However, most of the cracks were found to be less than 0.04 mm wide. No visible deformation was found and it was safe in the event of lateral pressure action without any slack or elimination of joints. The strain on the panel surface was measured 0.5 to 0.74 times the value of the FEM analysis. As a result of mechanical analysis through unit panel experiments and mock-up tests, the predictive equation of Design Guide for Ferrocement (549.1R-18 2018) is applicable to panel for formwork with a conservative approach.
Formwork at construction sites is a complex and dangerous process that takes a long time and over-injects manpower and temporary materials. In addition, efficient and improved formwork is required in terms of the construction period, safety accident, noise and vibration, protection of the environment, and cost. The final goal of the formwork efficiency is to develop prefabrication-permanent forms that can minimize temporary materials and waste materials by eliminating form assembly and removal operations at the site. Ferrocement has the characteristics that best suit these needs. Ferrocement, which is widely applied in various fields around the world, is a thin cement mortar matrix plate, a hard, ductile structure that has been reinforced by layering mesh reinforcement. It is also the first work of reinforced concrete. Ferrocement is lighter in weight than the P.C. (Precast Concrete) member, but can reliably withstand the lateral pressure of concrete casting. In addition, ferrocement has additional advantages such as ductile capacity, waterproof performance, durability, chemical resistance, and familiarity with residents, making it suitable for permanent formwork systems, which cannot be compared with any other material. In this study, through the unit panel experiments, ferrocement panels with Hydraulic Cement Grout (Non-Shrink), metal lath, and welded steel wire were manufactured. Several joint arrangements have been proposed at the factory to allow this ferrocement panel to be assembled on F-PSRC columns. As a result of the experiments of unit panel flexural strength, the longitudinal flexural performance of the mesh was about 1.8 times better than the transverse flexural performance. In addition, as a result of the unit panel experiment, the results of the experiment have a flexural strength of 1.27 to 1.77 times greater than the theoretical forecast value. After concrete casting mock-up tests, the surface condition of the panel was checked and cracks were produced in both directions. However, most of the cracks were found to be less than 0.04 mm wide. No visible deformation was found and it was safe in the event of lateral pressure action without any slack or elimination of joints. The strain on the panel surface was measured 0.5 to 0.74 times the value of the FEM analysis. As a result of mechanical analysis through unit panel experiments and mock-up tests, the predictive equation of Design Guide for Ferrocement (549.1R-18 2018) is applicable to panel for formwork with a conservative approach.