Applications of Perpendicular-To-Grain Compression Behavior in Real Wood Construction Assemblies

Authors

  • Craig T. Basta
  • Rakesh Gupta
  • Robert J. Leichti
  • Arijit Sinha

Keywords:

Construction applications, C┴ design, shear walls, wood-frame truss, wood-on-wood bearing

Abstract

Compression perpendicular to grain (C┴) of wood is an important property and has a drastic effect on serviceability of the structure. Typical C┴ loading scenarios include the bottom chord of a truss resting on the top plate of a shear wall and chords of a shear wall resting on the bottom plate. Present design values for C┴ are based on stress at 1-mm deflection for an ASTM block test. However, in real applications, loading conditions and deflection limits are much different from that administered during the test. There is a need to characterize C┴ behavior of wood in construction applications and compare it with current design codes. This study addresses that by testing two different assemblies involving C┴ loading, each with two different species of wood, to quantify the design C┴ based on the desired application and compare it with current design codes. Also, the effect of species and aspect ratio of assembly was characterized. Results suggested that the ASTM values significantly differ from the assembly values. Species of wood did not have any effect on the performance of the assemblies. A 2% strain offset method was proposed to determine allowable value for C┴ for a desired application. Adjustment factors based on loading configurations were suggested for calculation of design values.

References

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Published

2012-03-30

Issue

Number 2 / April 2012

Section

Research Contributions

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