The TCA has been made aware of some possible performance issues related to the use of specific plastic components in some concrete sandwich panels. A delamination of the concrete face layer of sandwich panels utilizing the TipCon connector was noted by a Tilt-Up contractor who used the system in at least two instances. In incidents where a delamination had occurred the corrective measures taken, which typically include drilling and epoxying a fiber composite connector through the face layer to the structural panel, proved to be very effective at securing the facia wythes. The contractor who reported the incident is in the process of evaluating all of the structures they have completed using the TipCon plastic connectors. Since the failures above a subsequent incident in Arizona has been reported to the TCA. In all of these cases, panel faces weighing thousands of pounds fell from the structural layer when the connector failed. According to the contractors reporting the incidents, the thermal plastic connectors utilized in this system can become brittle in cold temperatures and excessively ductile in warm conditions and are subject to long-term creep.

Sandwich panels using a glass fiber and thermal set resin technology, the same technology used in the remedial action on the above panels, have preformed successfully for over 30 years.