摘要
模拟火灾现场喷水灭火的情况条件,将高温下的混凝土喷水冷却,用扫描电子显微镜(SEM)分析混凝土的显微结构。研究发现,当受热温度低于300℃时,喷水冷却混凝土的显微结构与空气中自然冷却试样没有明显的差别。当受热温度达到300℃以后,冷却过程中的水会在混凝土中产生新的水化物,显微结构中发现有新的晶体。受热温度越高,新的水化物晶体就越多,同时混凝土的显微结构破坏越严重。这些特征可以用来鉴定火场中遇水冷却混凝土的受热温度。
The concrete on high temperature was cooled by water to simulate structure fire extinguishments by water spray. The microstructure of the samples was studied by scanning electron microscope (SEM). It was found that when the heating temperature is lower than 300℃, the sample in air with natural cooling and that with water cooling have no distinct difference in microstrueture. However, when the heating temperature is higher than 300℃, since the hydrate is destroyed on high temperature, the microstructure of air-cooling sample is destroyed. Because of the second-hydrate action, there will be new hydrate crystals produced in the water-cooling concrete. Higher is the temperature, more severely is the structure of concrete destroyed, with more new hydrate crystals generated in the water-cooling concrete. These characteristics can be used to evaluate the heated temperature of concrete in fire scene.
出处
《火灾科学》
CAS
CSCD
2006年第2期60-63,共4页
Fire Safety Science