Axial compression properties of bamboo/wood composite column constrained with sliced bamboo veneer

The purpose of this study was to investigate the enhancement effect of composite column on axial compression. Four full-scale composite columns and one Chinese fir (Cunninghamia lanceolata) column were fabricated and tested under axial compression load to study the enhancement effect of composite column. The compressive, bending properties of bamboo (Phyllostachys edulis) rod and Chinese fir were tested respectively. The ultimate axial load capacity, midpoint lateral displacement, failure mode of composite column and Chinese fir column were also investigated. The test results indicated that the harmonious coordination between bamboo rods and Chinese fir was shown under the axial load process, and the axial compressive strength 26.21 MPa and compressive modulus of elasticity 9.46 GPa of the composite column were increased significantly meanwhile the lateral displacement at the midpoint of composite columns was reduced by 9.61 mm compared with that of Chinese fir column, and the failure patterns of two types of columns were different. The results will provide a theoretical basis for the popularization and application of bamboo and Chinese fir composite columns.

Axial mechanical properties of small-diameter round timber short columns after exposure to elevated temperatures

A total of forty-eight specimens were tested, including forty short timber columns at elevated temperatures and eight short timber columns left untreated at ambient temperature. The main parameters explored in the test include column heights (135, 180, 225 and 270 mm), elevated temperature duration (10, 20, 30, 40 and 50 min) and section form. It was found that two new failure modes were generated after the specimens exposed to the elevated temperatures: splitting failure and bottom crushing, and the ultimate bearing capacity of the specimens with bottom crushing is the lowest. The ductility of circular specimens increases with the increases of column height. When the elevated temperature duration reaches 50 min, the plasticity of the specimens basically subside. The ultimate bearing capacity of the timber columns decreases with the increase of the elevated temperature duration and the maximum reduction is about 60% percent.