To verify the performance of Hy-Rib at construction joints, several tests have been carried out under research conditions, including the investigation of cores taken through the Hy-Rib at the joint. The evidence suggested that if there are differences, these favour the use of Hy-Rib permanent formwork.

The TWE panel trials used particularly fluid mixes. During concreting, extensive bleeding of water through the Hy-Rib was observed, particularly noticeable when the concrete was being vibrated. This seepage continued for at least 30 minutes AFTER completion of concrete placement and vibration. Subsequent detailed examination concluded that there was NO detrimental effect on the concrete quality near to the Hy-Rib face due to the bleed. Coring of several Panels further established that, if anything, the concrete properties had been enhanced in the Hy-Rib joint area.

In the TWE panel tests, 100mm diameter cores were taken. All the concrete was observed to be well compacted with NO evidence of continuous voidage, in fact the ends of cores cast against plywood noticeably contained less coarse aggregate. Cores were also taken through Panels 3 and 5; two across the scabbled joint where Hy-Rib had been removed, two at Hy-Rib positions and a further two, deliberately at laps of Hy-Rib sheets.

Examination at the ribs of the horizontally fitted Hy-Rib showed no cavities present. shows the core at the lap position of the Hy-Rib. TWE concluded that there was no problem with compaction at any position on the Hy-Rib.