Mechanical test results on wall panels built using the patented mortarless FlexLock system are reported. Walls are constructed using hollow stretcher concrete blocks ( 203 x 194 x 406 mm ) and universal corner units.
The blocks are slotted to permit assembly round a series of steel tensioning rods ( 11 mm diameter, minimum 406 mm centres ). The flexural tests of walls, 13 courses high, with post-tensioning stresses of 0.4-0.6 MPa, were comparable to those of mortared systems. Shear tests on walls of the same height gave results comparable to those of ungrouted, mortared systems.
It is proposed that the results were adversely affected by the low coefficient of friction between the blocks, a consequence of calibration prior to assembly, and also by the relatively low post-tensioning which was employed.