不同密度及尺寸聚苯保温板的温度-应变关系特性

Temperature-strain relationship characteristics of polyphenylene insulation boards of different densities and sizes

薄抹灰聚苯板外保温系统发生表面开裂甚至脱落的质量事故时有发生,为揭示该保温系统的劣化机制,从保温板类型、密度、尺寸、温度和时间等多因素研究聚苯保温板的温度-应变关系。结果表明:聚苯板随温度升高产生膨胀应变,一定时间内应变随着温度的升高而增大,超过平衡时间后会出现应力松弛现象,膨胀应变逐渐变小甚至可能转变为收缩应变;聚苯板尺寸增大,应变随之增大,也更易发生不可逆变形;大尺寸膨胀聚苯板密度减小,温度应变会相应增大;聚苯板在受到瞬时降温时,保温板会发生较大收缩。

In recent years,some quality accidents of surface cracking or even drop of thin plastered polystyrene board external thermal insulation system have been reported frequently. In order to reveal the deterioration mechanism of the thermal insulation system, the temperature -strain relationship of polyphenylene thermal insulation board is studied from the type, density, size, temperature and time of thermal insulation board. The results show that the expansion strain of polystyrene board increases with the increase of temperature in a certain period of time. When the equilibrium time exceeds, the stress relaxation will *occur and the expansion strain will gradually decrease or even change into shrinkage strain. With the increase of strain, irreversible deformation is more likely to occur, the temperature strain increases with the decrease of the density of large-size moulded board, when the polystyrene board is subjected to instantaneous cooling, the thermal insulation board will occur more contraction.