Evaluation of Bending Strength Ratios for Eastern Oak Pallet Lumber

Authors

  • John A. McLeod III
  • Thomas E. McLain

Keywords:

Strength ratio, pallet lumber, lumber defects, visual stress rating, modulus of rupture

Abstract

Visual stress rating using strength ratios is the only expedient and currently available method of assigning strength design values to pallet shook. In this study, the estimated bending strength ratio (ESR), determined from ASTM D245, and the actual bending strength ratio (ASR), determined through testing, were compared for over two thousand two hundred pieces of eastern oak pallet lumber. The ESR generally underestimated the ASR for stringers and deckboards with knots and slope of grain. The ESR increasingly underpredicted the ASR as knot size increased. The ESR consistently under-predicted the ASR throughout the range of severity of slope of grain. If assigners of design stresses for pallet shook use ASTM strength ratios, then conservative strength estimates will result; this is particularly true for low quality material.

References

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Published

2007-06-28

Issue

Number 3 / July 1987

Section

Research Contributions

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