Evaluation of Creep Performance of Structural Insulated Panels (SIPs): phase 3

Abstract

In this study, the creep deflection behavior of structural insulated panels (SIPs) was evaluated for creep-rupture equivalence to solid wood per ASTM D6815. The SIP specimens used in the study had 0.44-in. oriented strandboard (OSB) facers with a core of expanded polystyrene (EPS) foam. The following four groups of 15 SIP specimens each were examined: 12.25 in. thick with 1.2-lb/ft³ foam; 12.25 in. thick with 1.0-lb/ft³ foam; 6.5 in. thick with 1.2-lb/ft³ foam; and 6.5 in. thick with 1.0-lb/ft³ foam. To determine creep performance, both 12.25-in.-thick specimen groups were combined into a single group of 30 and both 6.5-in.-thick specimen groups were combined into a single group of 30. Specimens were loaded using dead weight in a four-point bending configuration. Per ASTM D6815, the constant load was maintained for 90 days and deflection of each specimen was measured hourly using linear variable differential transformers (LVDTs). Based upon the findings from this study, it is concluded that SIPs have equivalent creep–rupture behavior to solid wood per ASTM D6815 and the duration of load factors for lumber from table 8 of ASTM D245 are applicable to SIPs.

Citation

Senalik, C.A.; Khademibami, L.; Shmulsky, R.; Seale, R.D.; Ross, R.J.; Mohammadabadi, M.; Ward, K.; Williamson, T. 2024. Evaluation of Creep Performance of Structural Insulated Panels (SIPs): phase 3. Research Paper FPL-RP-720. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 7 p. https://doi.org/10.2737/FPL-RP-720