Analysis of extruded polystyrene short-term compression dependence on exposure time

Abstract

Extruded polystyrene is extensively used in many applications such as thermal insulation, packaging, structural use and buoyancy. In order to an effective use of this material it is essential to know its behavior under compression. The research in this work was carried out by using extruded polystyrene boards (F200, F300, F400, F500 and F700) which were produced by Lithuanian and Finland manufacturers. The changes of extruded polystyrene ultimate compressive stress σcr, ultimate strain, initial modulus of elasticity and thickness were determined right away after production and after a certain exposure time of specimens. It was noticed significant changes in strength characteristics after 45 days. Compression tests and conditioning of specimens were conducted at 23 °C ±2 °C ambient temperature and 50 % ±5 % relative humidity. Regression dependences of ultimate compressive stress σcr and ultimate strain on exposure time (from 10 to 326 days) were presented.