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The physical and thermal properties of concrete under high temperature are obtained in order to provide reference data for material models necessary to evaluate the structural integrity of steel plate concrete containment vessels (SCCV) under accident conditions. Various parameters, such as temperature, heating duration, temperature history (heating, cooling, and the post-cooling process), water binder ratio, cement type, and aggregate type, are considered. Data on the temperature dependence of physical properties (compressive strength, elastic modulus, strain at compressive strength, splitting tensile strength) and thermal properties (thermal expansion strain, specific heat, thermal conductivity) are obtained from concrete of the same mix proportion. The effects of the variables on the properties of concrete are clarified, and the differences between test results and existing codes, such as the Eurocode, are highlighted.

In performance-based fire safety design of buildings, design fires are assumed based on relatively coarse information of potential combustible objects described by the object name, weight, size and constituent materials. The fire effect is calculated by using assumed design heat release rate (HRR) to judge appropriateness of fire safety provisions. For this purpose, a simple estimation method to estimate design HRR curve (full time history of HRR) was developed. The method is based on summary of available experimental datasets of various combustibles, which were categorized into groups by their names and constituent materials. As a nature of categorized groups, there are two types of variations of HRR characteristics within each category group. One type is that the object size is almost constant within each category group. For this type, HRR curves are simply averaged over the available datasets in order to obtain the characteristic design HRR curve. The method was applied to chairs and sofas. The other type is that the object size varies within each category group. To develop size-dependent HRR curves, rates of fire growth and decay were averaged over datasets in the group. Maximum HRR and total heat release (THR) were correlated with surface area and weight, respectively.The method was applied to Christmas trees. By using the proposed methods, it is possible to establish a simple formula to represent full HRR diagrams by their category names.

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