In Situ Assessment Method of Wood Using Normalized Withdrawal Resistances of Metric-Screw Type Probes

Abstract:

Withdrawal resistances of wood have been applied for in situ assessment of wood in existing timber structures. The author had proposed method to estimate shear strengths of wood from measured withdrawal resistances of probes which are screwed into wood. In order to verify the accuracy of these estimated shear strengths by proposed methods, withdrawal resistance measurements and shear loading tests were conducted for wood. Single withdrawal resistance measurement was applied for wood specimens, and estimated shear strengths from withdrawal measurements were compared to the measured shear strengths by shear loading tests of wood. Correlation between the estimated shear strengths and measured shear strengths of specimens was reasonably good (R2=0.73). Multiple coaxial withdrawal resistance measurement which can provide distribution of shear strengths in cross-section of wood was also proposed. The average of estimated shear strengths by single withdrawal resistances was 7 percent less than that of measured shear strengths. The average of estimated shear strength by multiple coaxial withdrawal resistances was 3 percent greater than that of measured shear strengths. The single withdrawal measurements and multiple coaxial withdrawal resistances are available to estimate shear strengths of wood and shear strength distribution in the cross-section of wood. Estimated shear strengths obtained from these methods will be valuable for strength based in situ assessment of wood.

• Periodical: Advanced Materials Research (Volume 778)
• Pages: 217-224
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.778.217
• Online since: September 2013
• Authors: Nobuyoshi Yamaguchi
• Keywords: Assessment, Integrity, Probe, Shear Strength, Withdrawal Resistance, Wood

References

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