Information below taken from the "Air Force Research Laboratory Air Expeditionary Forces Technology Division".

Masonry Wall Retrofits

In the fall of 1999 AFRL began evaluating the LINE-X PAXCON® elastomeric polymer with concrete block walls. The LINE-X protective coating material is a proprietary elastomeric polymer that is flexible, ductile, and has modest strength. It can be sprayed using standard Occupational Safety and Health Administration (OSHA) safety practices for a hazardous material. The thickness of application is relatively easy to control, and the polymer bonds to a wide variety of surfaces.

We coated an 8-foot by 8-foot wall inside and out with the LINE-X polymer, and successfully tested it against 80+ psi blast pressures. Unreinforced concrete block infill walls typically shatter and fail at 2-4 psi pressures. Although the wall experienced large deflections and the concrete block inside the LINE-X polymer coating was severely fractured, the wall remained in place and no fragments entered the cubicle (as seen in the Post-Test image above). The LINE-X PAXCON® polymer coating effectively contained the shattered wall fragments and would have prevented serious injury to persons inside the building.