Because spalls in concrete are such a common problem, you might think that there is just one method, and one product to fix them. Unfortunately, that’s just not the case. Recently, two contractors in Lakeland, Florida had to repair very different kinds of spalls. Each repair required a different technique and a different repair material.
Bill Littleton of Concrete Restoration Services, Inc., needed
to repair spalled concrete at the expansion joints in a large
warehouse. For advice, he called the Prime Resins technical support
line. Bill was sent a copy of Prime Resins’ "Spall Repair
Instructions for Joint Edge Spalls" and to help Bill in his
discussions with the building owner, Prime Resins also sent a
copy of an article from Plant Services magazine titled
" Floor Investments Boost Productivity." Bill contacted
Florida Waterproofing Supply Inc., the local Prime Resins dealer
in St. Petersburg to help estimate the repair materials that would
be needed for the job.
When the owner approved the repair, Bill followed the instructions
that Prime Resins technical support had sent. He made a saw cut
outside the spalled areas, chipped out the loose and deteriorated
concrete, and vacuumed the excavation zone. Then he primed the
area using Prime Bond 3000 neat. Before the primer had fully cured,
he troweled down an epoxy mortar that he made by mixing oven-dried
sand and Prime Bond 3000. After the mortar cured, he saw-cut new
joints. The final step was filling the new joints with Prime Seal
5000 Semi-Rigid.
While Bill was repairing floor joints, Wayne Childree and DuWayne Barnes of L.T. Koppl Industries were dealing with a very different spall problem. This spall was on the interior wall of a concrete cooling tower at a waste burning plant, three feet below the water line. Because the power plant could not be shut down for the repair, the water in the cooling tower could not be drained. This meant that the spall would have to be repaired underwater. DuWayne called the Prime Resins technical support line and explained the problem to Michael Vargo. Michael recalled that a few years earlier, Prime Resins had worked with another customer to develop a special epoxy (PB48) for sealing underwater pilings. Michael pulled the specifications for this epoxy from the product library and found that it would be perfect for this project. Prime Resins prepared a formula for a flowable epoxy mortar that could be made from sand and the special PB48 formulation. DuWayne had a plywood form constructed over
the spall and anchored it to supports in the cooling tank. He mixed the mortar and poured it behind the form. Three days later, the form was removed and revealed that the spall had been completely repaired.
These two Lakeland, Florida contractors solved their spall repair
problems with technical support from Prime Resins. Michael says
that helping contractors develop a repair strategy is the most
interesting part of his job. As one technical support rep said,
"It’s really satisfying when I can recommend the right
method and the right product to solve a customer’s problem.
It’s too bad that we usually get calls for help only after
one to two attempted repairs have failed."
If you would like a copy of the Prime Resins’ "Spall
Repair Instructions for Joint Edge Spalls," or help with
a repair project, call the technical support line at 800-321-7212.
Try using the following "defect cost formula" for a joint edge spall that causes a 2 second slow down in a fairly active distribution operation:
2 seconds x 20 trips/hour = 40 seconds/hour
x 8 hours/day = 320 seconds/day
x 5 days/week = 1,600 seconds/week
x 52 weeks/year = 83,200 seconds/year
= 23.1 hours/year x $15.00/m an-hour
= $346.50 cost/year
To carry the study further, multiply this cost by the number of similar defects in the floor(s).
