This report summarizes the experimental works that was carried out for a one-year research project developed as the continuation of previous research projects on the subject of light weight hollow core sandwich panels. The experiment focused on the investigation of creep behavior of light weight hollow core panel under long term static loading and high humidity conditions and its correlation with short term properties. Five types of surface panels were used, namely, 3.2 mm thick high density fibreboard with birch veneer on both sides, two thicknesses of M2 grade particleboard (6.3 mm and 9.5 mm) and two thicknesses of medium density fibreboard (6.3 mm and 9.5 mm). All panels were fabricated to the same final sandwich thickness of 45 mm using cell size of 12.7 mm Kraft paper honeycomb.
The results of the experiment show that the strongest facing material used to make the sandwich panels was the 3.2 mm hardboard with wood veneer lamination on both sides running along the long axis of the panel and test specimen, followed by the 6.3 mm MDF and the 9.5 mm MDF. The experiment demonstrated that exposing the panels to high humidity could cause strength loss of up to half of the original strength. However, the result of the experiment also suggested that it would be difficult to accurately predict the long term creep behavior of the sandwich panels using their corresponding short term flexural properties as the correlation between creep deformation and flexural properties was rather weak under the testing procedure and condition used.