Compressive behavior of damaged timber columns: Experimental tests, degradation model, and repair method

Abstract

Local decay often appears in columns of traditional timber structures and negatively affects their compressive behavior. In this study, axial compression tests were conducted on four column specimens with different damage degrees, which were simulated by artificially removing local wood, and on three damaged column specimens that were reinforced by filling with different wooden blocks to investigate the degradation performance and repair ability of timber columns. The failure mode, load-axial displacement curves, load-lateral deflection curves, varied load-carrying capacity laws, and different stiffness of the locally damaged and repaired timber columns were obtained and analysed. The study results indicated buckling failure was observed on all column specimens. The compressive strength and stiffness decreased significantly with an increase in the damage degree for the locally damaged timber columns. Moreover, a theoretical degradation model was proposed to predict the compression strength of locally damaged timber columns, and a good agreement was obtained between the theoretical and experimental results. This degradation model can provide a theoretical basis for evaluating the compression behavior of damaged timber columns. For repairing timber columns, the local damage section can be filled with a wooden block; the larger the length and elastic modulus of the block, the better the repair effect. The compression behavior of the damaged timber columns repaired using the optimized wooden block could restore to that of the intact timber column.