Tests of cellular plastic (XPS and EPS) insulation boards, resistance to cyclic compressive loading with square-wave load (NT TR 547)

Abstract

  Cellular plastic boards can be used in railway embankments in order to lower the pressure on the underground and to provide insulation. The long-term deformation  resistance is of great importance for this application. In co-operation with the Swedish and Finnish railway authorities and Tampere University of Technology, SP has designed a test method, SP-method 2687 “Resistance to cyclic compressive loading with square-wave load”, for this material and application. The aim of this project has been to evaluate how the size of the test specimen influences the results and to compare results from two laboratories. The project has comprised a total of 14 tests, of 2 different types of cellular plastic (XPS and EPS) and 3 different specimen sizes. Two tests have been carried out at Tampere University of Technology, the other 12 at SP. The results from the tests of the XPS-material show a relationship between the specimen size and the residual deformation. However, in the case of EPS-material no such relationship was established.