Papers by Keyword: Fire

Abstract: Fire engineering is primarily to prevent loss of life or injury during a fire. Obviously the best way to achieve this is to prevent ignition, minimizing fire spread and smoke, dying the fire before it has fully developed. When this is not possible, when the fire is fully developed, structural elements must guarantee sufficient fire resistance. If containment methods fail, structural integrity must stay for a period long enough to evacuate occupants and firemen put out it. This investigation studies the bearing capacity of GFRP reinforced concrete element, its fire resistance, variations of its mechanics characteristics and its bonding to concrete when temperature rises, together others changes that may occur in the element.

Abstract: For making sure the dry bay ignition and fire, it’s necessary to calculate the number and the sizes of the droplets and determine the mass flow rate of the fuel induced by high-speed impact and penetration of a rigid projectile into fuel tank. An analytical model is founded and the method for calculating the initial leaking velocity of the fuel is determined. It gives the equation for calculating the drop size distributions of fuel and the Sauter mean diameter (SMD) of droplets, through the Maximum Entropy Theory and the conservation for mass. Using the Harmon’s equation for SMD,the fuel droplets SMD can be calculated. Results shows that the initial leaking velocity of the fuel is about linearly increasing with the velocity of the projectile, the SMD of fuel droplets increases with the hole size of the fuel tank which induced by the penetration of the projectile and linearly decreases with the velocity of the projectile. The results can be used for the ignition and fire analysis of the dry bay adjacent to fuel tanks.

Abstract: The mechanical properties of fire-damage reinforced concrete columns strengthened with bonded steel angles were studied. Nine specimens were tested, including three normal temperature controlled columns, six heated under ISO834 standard fire. After exposure to fire, three of the six were rehabilitated with the bonded steel angles. It was shown by test results that the destructive properties of reinforced concrete columns with bonded steel angles may change and the small eccentric compression specimens may become large eccentric compression due to the steel angles increased the amount of steel in the tension zone of the specimen. In this research, compared with these under normal temperature, the bearing capacity of specimens which were exposure to fire was only ranged from 0.25 to 0.37 times. But the bearing capacity of specimens rehabilitated by the bonded steel angles can increase to 2.86 to 4.04 times of the originals and it can reach to the level of that in normal temperature.

Abstract: In order to understand the fire safety of the various types of buildings, we need more flexible and efficient performance-estimating methods to verify fire protection safety in various types of buildings. Assuming can utilize computer fire simulation software CFAST / FDS + Evac to analyze Taiwan's domestic fire cases, in order to understand in the different fires heat flow transfer, and toxic smoke diffuse, and human evacuation to escape, and other important fire parameter characteristics, in the building the fire protection safety evaluating to produce the efficiency. This study is used cases of fires in four-story old-style residential and commercial mixed-use buildings to explain building fire performance-based numerical evaluation methods, and to provide quantitative data and reference information in Taiwan performance-based codes creating and the fire protection to project design is helpful in the buildings.

Abstract: The assessment method of fire-damaged concrete bridge with prestressed hollow core plate girders was presented in this paper. The historical sketch of assessment of fire-damaged concrete structures was briefly introduced. One fire-damaged concrete bridge with prestressed hollow core plate girders was shown as an example. The process of assessment of fire-damaged concrete bridge with prestressed hollow core plate girders was provided. According to the assessment results, methods of repair and strengthening were presented for different fire-damaged level of prestressed hollow core plate girders. The research results could help expand use of fire-damaged assessment and repair of prestressed concrete bridges.

Abstract: In order to research the calculation method of shear capacity for fire-damaged reinforced concrete (RC) beams, the reason of drop of shear capacity was analyzed from material properties and transfer mechanisms of RC beams after fire. Formulas of shear capacity were suggested for fire-damaged RC beams. Based on test analysis, the values of reduction factors of shear capacity were proposed under concentrated load. The results show that suggested calculation method is capable of predicting shear capacity of fire-damaged RC beams exactly. The values of reduction factors of shear capacity need further experiments research.

Abstract: Boilover is acknowledged as one of the most harmful fire in oil tank fire. A small-scale oil tank boilover apparatus was established to study the flame behavior during boilover process. Visualization experiments were also conducted to discuss the mechanism of boilover formation. The results indicate that boilover process can be divided into three stages: quasi steady combustion stage, boilover premonitory stage and boilover stage. The formation of boilover results from the reciprocity of bubbles and oil vacuoles generated by absorbing energy released from combustion reaction.

Abstract: A finite element model for square reinforced concrete stub column under overall fire and axial compression is developed. The temperature of columns subjected to simulated heating and cooling standard fire and the maximal temperature field were determined. The creep of steel bars, bond slip between steel bars and concrete, transformation of material properties were considered in the force analysis. The deformation under overall fire and the load bearing capacity of the column with initial load after fire are provided.

Abstract: Building fires, which may cause failure of buildings, occur frequently in cities all over the world. Composite structural members, such as concrete filled steel tube columns and steel-decked composite floor slabs, are being increasingly used in buildings for their dual advantage of excellent load bearing capacity and fire resistance. Because the heat transfer across a steel-concrete interface is difficult to model using ordinary elements, most existing finite element analysis models ignore the effect of thermal contact resistance. In this paper, several two- and three-dimensional new thermal resistance elements (referred as TRE for brevity), which have been embed in the special purpose finite element software TFIELD coded by authors, are proposed. Two numerical examples are given. Numerical simulating results demonstrate that the proposed thermal resistance elements are extremely effective.

Abstract: This is a case study of cottage housing in Taiwanese military dependents’ villages that are primarily wooden structures with brick walls. When a fire ignited in one of these structures, sufficient air on the exterior of the building promoted the rapid ignition of the wooden structure. Because residents were a woman and child who lacked fire safety and escape knowledge, the fire resulted in two deaths. When fires ignite in wooden structures, toxic particulates in the smoke generated from the burning and decomposition spread rapidly because of thermal buoyancy effect, causing difficulties for escape and rescue. This research utilizes the fire dynamics simulator (FDS) software to simulate the fire scenario to discuss the impacts of smoke diffusion at a fire site and analyze the main causes of the fire. We also provide suggestions in the hope of offering information on fire safety precautions for this structure type to prevent future similar disasters.