Papers by Author: Soon Wook Choi

Abstract: To protect underground structures and passengers from fire, it is essential to characterize fire-induced damage on the construction materials for underground structures. However, it is almost impossible and uneconomical to carry out full-scale fire tests in tunnels that are under public usage. In this study, a high temperature furnace capable of simulating RABT (Richtlinien für die Ausstattung und den Betrieb von Straßentunneln) fire curve was newly designed and manufactured. In the fire tests, furnace temperature is set to reach 1,200
within five minutes after ignition. The temperature of 1,200
was maintained for one hour, and the fire was extinguished after two hours had elapsed. From the temperature measurement by thermocouples embedded in test specimens, the depth of lost concrete was estimated to reach approximately 20 cm from the surface that was exposed to fire. In addition, the alteration of physico-mechanical properties and microstructures of concrete segments after fire tests were investigated from core specimens. The results show that the deterioration of material properties was up to 10 cm from the surface of the remaining concrete block