Fire damage to concrete can be estimated in many ways, and these can be classified as destructive or non-destructive testing methods. Destructive testing generally results in higher accuracy，but such testing is not always possible at fire sites due to the resulting damage to walls. The development of a non-destructive, high-accuracy testing method would therefore be of great benefit. This study considers a new non-destructive, non-contact method for detecting the extent of fire damage to concrete through the use of aerial ultrasonic waves and optical equipment. We attempt estimation of fire damage for a concrete sample with reference to an actual site. In addition, we also attempt estimation of fire damage for a concrete wall at the actual site where a fire was artificially started in a multi-unit housing building. Results demonstrate the effectiveness of the proposed method for comparing the temperature distribution on a concrete wall exposed to high temperatures at the actual fire site, and estimating the extent of fire damage.
RIP (Reduced Ignition Propensity) cigarettes have been drawing attention as a measure for reducing the loss of fire caused by a lit cigarette in Western countries. On the other hand, the lifestyle in Japan is a little different from those in such countries. In order to examine the effectiveness of RIP cigarettes in the context of real fire situations in Japan, we conducted the experimental study using the conventional cigarettes and RIP cigarettes as ignition sources and some types of futon made of different filling and outer materials as the ignited materials, assuming smoking in the futon. Then, we examined the results statistically to see whether or not there is the difference in ignition propensity between conventional and RIP cigarette in relation to the types of futon and cigarette placement conditions respectively. As a result, experimental results show no significant difference between conventional cigarettes and RIP cigarettes in terms of the occurrence rate of continuous smoldering of futon under all of experimental conditions in this study, while significant differences were observed between different futon types and between different placement conditions respectively under some experimental conditions.
The 2011 Great East-Japan Earthquake that occurred on March 11, 2011 caused large-scale and wide range fire damage. Also, this earthquake showed a distinctive feature such that there were quite many fires caused by tsunami directly and/or indirectly in the regions, which were more or less affected by the tsunami. Therefore, the authors refer these fires to “tsunami-induced fires” in this paper. On the other hand, regarding the fires in the cities and towns that do not have coastal zone and were not affected by tsunami, we treated them as “earthquake-induced fires.” Since the mechanism of occurrence of “tsunami-induced fires” differs largely from that of “earthquake-induced fires,” we think these two types of fires should be analyzed separately. In this paper, therefore, we describe the overview of fires following the Great East-Japan Earthquake such as regional distribution of fires and patterns of ignitions. Also presented are the findings from the results of the analysis on the relation between the incidence of “earthquake-induced fires” and the seismic intensity.