PURPOSES : When fire event occurs in tunnel the reinforced concrete is exposed to very high temperature at a very short time period. This study investigates the tensile behavior of steel rebar that experienced high temperature. METHODS : The steel rebar was exposed to 200, 400, 600, and 800℃ following the ISO 834 temperature-time fire curve. Hightemperature- exposed steel rebars were tested using the UTM for their yielding and tensile strengths, and elongation rate. RESULTS : Up to an exposure temperature of 600℃, the tensile properties of the rebar did not vary considerably. However, at 800℃ (which corresponds to a temperature rise time of approximately 22 min), the rebar lost its yielding and tensile strength by approximately 27 and 13%, respectively, compared to the control specimen. Further, the elongation rate increased after exposure to 600℃. The above fundamental tensile test results can be a good reference for future guidelines in the repair manual for tunnels after severe fire events. CONCLUSIONS : When steel rebar experiences high temperatures of 800℃, the yield strength of the rebar reduces approximately 27%. This strength reduction can cause severe structural damage to tunnels that use reinforced concrete as the primary structural elements.

콘크리트의 사용은 건축 및 토목분야에서 널리 사용되어 왔으며, 센서는 콘크리트에 기능적 특성을 위해 사용되어 왔다. 손상을 스스로 나타내는 콘크리트는 이미 개발되고 있는 중에 있다. 본 연구에서 온도보상센서는 금속의 선형팽창과 체적변형을 이용한 센서이다. LED는 광센서로 고휘도이며, 이들 센서의 가격은 저가격이다. 화재하중으로 인하여 콘크리트 보의 온도보상센서가 동작하는 동안 지상 보의 LED동작으로 콘크리트 부재의 온도상승을 예측한다. 본 연구에서는 부재의 손상감지를 위해 간단한 계측방법을 이용하여 화재자현을 스스로 나타내는 콘크리트 보를 개발하기 위한 기초적 연구이다.

This paper describes "the remote automatic diagnosis and repair system which automatically reads the problems such as "out of order" occurred on equipment at customer's equipment from a remote computer center using HTTP(hyper text transfer protocol). It shows the scheme of the network configurations and features of the system. In addition, a way to implement the overall system, the specific functions of unit, and the operational specifications between the center's computer and customer's computer are also presented.also presented.

In this study, fire test of predicting fire behavior(fire growth rate, temperature of compartment, etc.) were performed for fire safety diagnosis in buildings. From this test, fire propagation for each combustible was identified, which was delayed compared to the summed heat release rate fo a single combustible. Also, comparison with Matsuyama model allowed improvement in the modeling of the process of fire spreading to nearby combustibles

This study investigated the House of Commons through the combustion characteristics of the flammable after performing the experiment for predicting fire constellation is to present basic material. Combustibles of the House of Commons was established to investigate through the standard model, such a list of proposed standards for the combustible