This standard specifies the methods for sampling, conditioning, and conducting compression tests on full-size timber props used for support in mines. It aims to provide a uniform procedure for determining their load-bearing capacity and behavior under axial load.
Method of tests for timber props for mines
Quick Reference Values
Standard test temperature27 ± 2 °C
Standard relative humidity for conditioning65 ± 5 percent
Loading head bearingThe machine shall have a spherical bearing block for the loading head
Accuracy of load measurement± 1 percent of the indicated load
Rate of movement of testing machine headNot to exceed 0.05 mm/s per cm of prop length
Key Formulas
Compressive Strength (σ) = P / A — where P is the maximum load and A is the cross-sectional area at the point of failure
Practical Notes
The strength of timber is highly sensitive to moisture content; ensure props are conditioned to the specified 12% moisture level for comparable results.
Careful visual inspection for defects such as knots, splits, and decay is essential before testing, as these significantly influence the prop's strength and failure mode.
The rate of loading must be controlled as specified, as a faster rate can yield artificially high strength values.