TECHNICAL PAPERS
Feb 1, 1986

Design Criteria for Epoxy Repair of Timber Structures

Publication: Journal of Structural Engineering
Volume 112, Issue 2

Abstract

The repair of timber structures requires the same careful engineering design as that of new structures. However, practically no information is available that allows the engineer to compute either allowable or actual stresses for repair alternatives. Based on both theoretical and experimental studies, a methodology for computing both actual and allowable glue line shear stresses is presented here. The actual glue line stress is computed as an average shear stress. The allowable stresses are given as formulas which are functions of the wood species, grain orientation, allowable wood shear stress, and lap length to member thickness ratio. Several epoxy formulations are considered and a method for evaluating other epoxies is presented. Numerical examples are given to illustrate the approach for both predicting the strength and designing a repair scheme. Through the use of the design techniques presented here for epoxy repair of timber, the engineer can rationally decide: (1) Whether the proposed repair will be structurally adequate; and (2) how to modify the design if the predicted load capacity of the joint is too low.

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References

1.
Avent, R. R., “Factors Affecting Strength of Epoxy‐Repaired Timber,” Journal of the Structural Division, ASCE, Vol. 112, No. ST2, Feb., 1985, pp. 207–221.
2.
Avent, R. R., Emkin, L. Z., Howard, R. H., and Chapman, C. L., “Epoxy‐Repaired Bolted Timber Connections,” Journal of the Structural Division, ASCE, Vol. 102, No. ST4, Apr., 1976, pp. 821–838.
3.
Avent, R. R., Emkin, L. Z., and Sanders, P. H., “Behavior of Epoxy Repaired Full‐Scale Timber Trusses,” Journal of the Structural Division, ASCE, Vol. 104, No. ST6, June, 1978, pp. 933–951.
4.
Avent, R. R., Issa, R. R. A., and Baylot, J. T., “Weathering Effects of Epoxy‐Repaired Timber Structures,” Structural Uses of Wood in Adverse Environments, Ed. by Meyer and Kellogg, Van Nostrand Reinhold Company, New York, NY, 1982, pp. 208–218.
5.
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6.
Avent, R. R., Sanders, P. H., and Emkin, L. Z., “Epoxy Repair of Timber Structures Comes of Age,” Construction, Adhesive Engineering Company, Vol. 13, No. 2, September, 1978, p. 6.
7.
Avent, R. R., Sanders, P. H., Emkin, L. Z., “Structural Repair of Heavy Timber with Epoxy,” Forest Products Journal, Vol. 29, No. 3, Mar., 1979, pp. 15–18.
8.
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15.
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16.
Sanders, P. H., Emkin, L. Z., and Avent, R. R., “Epoxy Repair of Timber Roof Trusses,” Journal of the Construction Division, ASCE, Vol. 104, No. CO3, Sept., 1978, pp. 309–321.
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Go to Journal of Structural Engineering
Journal of Structural Engineering
Volume 112Issue 2February 1986
Pages: 222 - 240

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Published online: Feb 1, 1986
Published in print: Feb 1986

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R. Richard Avent, M. ASCE
Prof. of Civ. Engrg., Louisiana State Univ., Baton Rouge, LA 70803

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