This paper aims to develop numerical models for seismically-deficient reinforced concrete columns retrofitted using a fiber-reinforced polymer jacketing system under blast loading scenarios. To accomplish the research goal, a coupling model reproducing blast loads was developed and implemented to the column model. The column model was validated with a past experimental study, and the blast responses were compared to the numerical responses produced by past researchers. The validated modeling method was implemented to the non-retrofitted and retrofitted column models to estimate the effectiveness of the retrofit system. Based on the numerical responses, the retrofit system can significantly reduce the peak dynamic responses under a given blast loading scenario.

This study develops finite element models for seismically-deficient reinforced concrete building frame retrofitted using fiber-reinforced polymer jacketing system and validates the finite element models with full-scale dynamic test for as-built and retrofitted conditions. The bond-slip effects measured from a past experimental study were modeled using one-dimensional slide line model, and the bond-slip models were implemented to the finite element models. The finite element model can predict story displacement and inter-story drift ratio with slight simulation variation compared to the measured responses from the full-scale dynamic tests.

본 논문은 FRP보강시스템에 의한 철근콘크리트보의 보강설계에 대하여 소개하고 있고 ISIS CANADA-Design Manual No. 4(2001) 및 KCI-2012의 설계 코드를 고려하여 연구가 수행되었다. FRP보강시스템에 의한 철근콘크리트보의 보강 설계순서 도가 제시되었으며, 보강설계해석프로그램을 소개하였다. 연구의 검증은 참고문헌과의 비교를 통해서 이루어졌다. 또한, 복철근 직사각형 보와 T형보의 정밀 분석을 통하여 보강 설계 순서도를 수정, 보완하는 경우를 제시하였다. 구조설계자는 본 프로그램 을 이용하여 FRP보강시스템에 의한 노후 철근콘크리트보의 보강설계를 쉽게 수행할 수 있다. 따라서 본 연구가 FRP보강시스템 의 최적화된 설계 및 제작 등에 실질적인 지침서가 될 수 있을 것으로 기대된다.

Existing reinforced concrete building structures have seismic vulnerabilities due to their seismically-deficient details resulting in non-ductile behavior. The seismic vulnerabilities can be mitigated by retrofitting the buildings using a fiber-reinforced polymer column jacketing system, which can provide additional confining pressures to existing columns to improve their lateral resisting capacities. This study presents dynamic responses of a full-scale non-ductile reinforced concrete frame retrofitted using a fiber-reinforced polymer column jacketing system. A series of forced-vibration testing was performed to measure the dynamic responses (e.g. natural frequencies, story drifts and column/beam rotations). Additionally, the dynamic responses of the retrofitted frame were compared to those of the non-retrofitted frame to investigate effectiveness of the retrofit system. The experimental results demonstrate that the retrofit system installed on the first story columns contributed to reducing story drifts and column rotations. Additionally, the retrofit scheme helped mitigate damage concentration on the first story columns as compared to the non-retrofitted frame.

Since it is impossible to predict earthquakes, they involve more casualties and property damage compared to meteorological disasters such as heavy snow and heat waves, which can be predicted through weather forecasts. This has highlighted the need for seismic design and reinforcement. Recently, the use of composite materials as reinforcement has surged because steel plate reinforcement and section enlargement are likely to result in increased weight and physical damage to structures. This study evaluates the seismic performance of panels created from composite materials, and their guide systems. The specimens were miniature versions of actual steel structures, and displacement loads were applied in the transverse direction. Seismic performance was found to improve when structures were reinforced with seismic panels.

This research presents effectiveness of fiber-reinforced polymer column jacketing system for a non-ductile reinforced concrete building frame constructed before the 1970s. To investigate the retrofit effects, a series of full-scale dynamic tests for the retrofitted test frame was conducted, and the dynamic responses were compared to those of the non-retrofitted test frame. The effectiveness of the retrofit system was investigated in terms of response reductions, damage mechanisms and drift concentration factors.

This paper presents a finite element analysis to evaluate thermal conductivity of FRP (Fiber Reinforced Polymer) retrofit system in reinforced concrete structure. Especially, this paper focused on near-surface-mounted retrofit method; FRP is mounted into the groove after making a groove in concrete. Midias-FEA program was used to analyze the case that the epoxy was covered by various board to resist fire such as, calcium silicate or alumino silicate board. Analysis results give that the prediction of temperature transition from surface is possible by FE analysis and the result can be used to evaluate fire resistance of certain fire proof materials in FRP retrofit system.

FRP 시스템으로 보강된 철근콘크리트 단면 대부분이 철근콘크리트로 구성되어 있어 휨해석 및 휨설계를 직사각응력블록을 이용한 강도설계법에 의존하는 경향이 있다. 그러나, 보강단면의 인장철근 및 FRP시스템에 의한 인장력이 부족한 단면의 FRP 시스템의 변형률이 인장파단변형률을 초과하면 강도설계법을 적용할 수 없는 해석상 모순에 빠져든다. 인장철근과 탄소섬유시트에 의한 인장력이 낮은 탄소섬유시트 보강보 실험에서 콘크리트 최대압축변형률이 0.003보다 낮은 것으로 측정되었을 뿐 아니라 최대휨모멘트는 강도설계법으로 산정된 공칭휨모멘트보다 작은 것으로 측정되어, FRP 시스템 보강단면의 공칭휨모멘트 산정에 강도설계법의 적용한계가 있는 것으로 나타났다.