A method of test was developed on Panel 3 and 5 by arranging “blocks” that could be levered off using an hydraulic ram. The results are summarised in the Table below. Such interfaces have never previously been examined in this way, and although only two of each item were tested, did show conclusively that the Hy-Rib joint was much stronger than a scabbled joint.

A useful subsequent test was carried out on the six 100mm circular cores to test bending strength (flexure) across the joints. A simple arrangement, shown here was used and the results are summarised in the Table below. It was significant that the lapped Hy-Rib with its minimum two layers of meshed material at the lap performed better in flexure than a single layer of Hy-Rib.

Although it is recognised that detailed conclusions cannot be established from only two tests, the results in shear and bending confirm that the failure loads in Hy-Rib joints are at least 18% stronger than those achieved with conventionally scabbled joints.

Summary of shear and core flexure tests from TWE panel trials