CCC Job #3303

StarPlus Energy Kokomo Battery Plant

STATEMENT OF PROBLEM:

After pan filled stairs were poured and opened to foot traffic, a number of aluminum nosings were found to be loose or have a hollow void under them. They made a specific noise when walked upon. 

ROOT CAUSE:

Improper care when setting the nosings into the wet concrete. Nosings should be vibrated or tapped into place to ensure proper concrete coverage around the embed studs on the backs of the nosing.

COURSE OF ACTION:

Rather than chip out and reset the nosings, which would have caused logistical problems for the jobsite, it was determined that an injectable epoxy product be used.

The team ordered DURAL 452 LV by Euclid Chemical. This is a very low-viscosity epoxy and it flows very well in small voids. The team ordered small plastic bottles with thin metal injection ports (see photo).

The team caulked the underside of each tread to be repaired, so the epoxy would not leak out, drilled a 1/16" hole in the nosing and injected the DURAL 452 LV into the applicator bottles. The bottles were then used to get the epoxy into the drilled hole.

Within a couple of hours, the nosing was no longer loose, and the hollow void under it was filled. 

This saved the team many hours of rework.

LESSON FOR FUTURE PROJECTS:

Ensure stair nosings are properly vibrated or tapped into place. Check for hollows under the treads using a wooden mallet. Re-vibrate if required.