A mathematical model for estimating structural performance of reinforced concrete beams exposed to fire has been set up by combining two mathematical submodels for calculation of temperature and structural performance. And the validity of the model has been verified by experiments on two dimensions of full scale beams. For listing the fire damage of 720 types of beams with different specifications such as dimensions, total amount and compressive/tensile cross-sectional area ratio of reinforcing steel bars to be included in the beams, the mathematical model has been applied. Some of the results are presented as examples in this paper.
The heat generation values for the typical smoldering fire sources which have been proposed as the ISO Standard on Fire Detector Test were estimated experimentally based on oxygen consumption and weight loss rates. Heat generation values of smoldering wood and cotton wick showed 1/10 - 1/3 of those of flaming phase. The heat generation rate which was proposed as the Standard of ISO Fire Source was 1.5 kW and gave excess temperature of 2 - 2.5°C under the ceiling of the proposed ISO test room. It was found experimentally using the test room and proposed smoldering fire sources that the hot layer under the ceiling of which excess temperature of 2 - 3°C stopped the penetration of updraft smoke from the smoldering source through the thermal interface. It should be necessary that the exact definition on vertical thermal condition for the proposed ISO Test method to get repeatability, reliability, and sensitivity of the fire detector tests.
General geometry and height of diffusion flames and the height-dependence of centerline temperature above propane burners of relatively low heat release rate for the fuel size are described. The flame behavior is classified into 3 regimes according to the difference in the height-dependence of centerline temperature and in the general behavior of the flame. Flame height is represented as a function of Q∗ = Q/ρ0CpT0g1/2D5/2. The criterion for the adequacy of the concept of "virtual source" for the prediction of centerline temperature from the point-source turbulent plume theory is discussed.
Methodologies on systems approach might be useful for the synthetic estimation of building fire safety. However, the meaning of their formula often seems obscure or irrational. This paper has a discussion on the characteristics of systems-structures applied to each method. For example, Gretener's method is basically composed by a divisional formula, which belongs to an emphatic expression with the ratio of hazard potential to safety countermeasures. The other discussions are on the point-making methods determining an effectiveness of fire facilities, with a tentative result of double effectiveness of sprinkler systems to heat detector equipments.
The design method of building structures has been trending from allowable stress design method to ultimate state design method. The ultimate state design method is based on the assumption that load bearing and deformation capacity of plastic hinges are ensured sufficiently. Using the ultimate state design method in fire engineering desing, it is necessary to investigate load bearing and deformation capacity at elevated temperature. In this study, the load bearing and deformation capacity of H shaped steel members are obtained experimentally under three stress conditions at elevated temperature.
Software-controlled fire detecting installations are of increasingly gowing importance and attraction. The paper discusses the advantages as the main reasons for this fact. In addition it gives an indication of the problems to be solved and the inherent failure sourcses. The main applicable design rules are derived from the principle that failure sources have to be avoided and where they are unavoidable their effects have to be minimized. The basic design approaches are discussed in this context. It is mentioned that in practice a combination of several aspects has to be applied for several reasons. Testing is necessary on the different levels of the design, development and application process. The contribution discusses the possible test philosophies for type testing in some detail and mentions a special test procedure for software-controlled fire detection systems which has been discussed in the European community and which is a compromize between a rigorous functional (dynamic) testing and a documentation check. It is likely to give suitable over-all indication of the system quality, it checks several key specifications and it keeps the testing expenses at an acceptable level. It is shown that black-box testing is not possible.