There have been the growing number of high-rise buildings all over the world in the past few decades. In these high-rise buildings, one of the most crucial safety issues is an evacuation in a fire, which may require total evacuation, if a fire expands to a large size. For a total evacuation, there are two types of methods such as “simultaneous evacuation” and “phased evacuation”.
In this study, first, the authors conducted the two questionnaire surveys regarding a total evacuation to building managers and also participants of a fire drill in high-rise buildings. From the results, it was found that the phased evacuation is more preferable compared with simultaneous evacuation. Second, the authors developed a method to estimate an optimum evacuation plan for phased evacuation in a high-rise building. This method can immediately output the waiting-time and floors to evacuate per phase by inputting values such as a fire floor, the number of evacuees on each floor in a particular fire scenario, and so forth. This method is useful not only for mitigating congestion inside stairs, but also for preferential evacuation for evacuees near a fire floor that has a higher fire risk. In addition, this method has a function to shorten the completion time of a total evacuation.

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This paper reviews up-to-date research and development on improvement of flame retardancy of some polyolefins compounded with expandable graphite, focusing particularly on the related works published in the past decade. Although polyolefins seem to be somewhat more difficult to improve the flame retardancy than any other polymeric materials such as polyurethane, great effort has recently been made to improve the flame retardancy of high-density polyethylene (i.e., HDPE) and polypropylene (i.e., PP) as well as low-density polyethylene (i.e., LDPE) and ethylene - vinyl acetate copolymer (i.e., EVA), compounded with expandable graphite, by developing expandable graphite with improved performances or by searching for formulations for polyolefin composites with improved synergistic flame-retardant effect when compounded with expandable graphite.

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This paper reviews up-to-date research and development on improvement of flame retardancy of some polymeric materials other than polyolefins, compounded with expandable graphite, focusing particularly on the related works published in the past decade. The literature survey has revealed that two different types of studies for improvement of flame retardancy of polymeric materials containing expandable graphite have been conducted; i.e., one is to develop expandable graphite with improved performances, and the other is to search for formulations for polymeric composites with improved synergistic flame-retardant effect when compounded with expandable graphite. In addition, it is also noted that there has been a recent tendency to try to compound expandable graphite not only with polyurethane but with some other polymer matrixes, such as polystyrene, acrylonitrile-butadiene-styrene (i.e., ABS) resin, polylactide, cyanate ester resin, epoxy resin, silicone rubber. etc.

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