car progression system rabbit StrUCTURAL REPAIRS
TIME LIMITED, LIVE OPERATION Renovation OF CRITICAL INFRASTRUCTURE
Project Date: 2024
Facility: Western Canada
Railway Drain RENOVATION TO IMPROVE CAR PROGRESION SYSTEM INTEGRITY
After demolition on-site, SureBond and Rail Shop Services modified our repair protocol to re-build the drains next to the rabbit track, with steel rebar support and chemical bond of repair materials to the drain walls.
The car shop lines needed to be returned-to-service in this busy shop asap. The progression system needed to be reliably restored by repair.
The rabbit channels being proximal to the drains was the cause of the damage that was being incurred to the rabbit system (ie. insufficient concrete encasement around the rabbit on one side)
Another view showing the rabbit next to the drain.
Concrete replacement areas were identified for demolition, and replacement with better rebar support. These replacements were very thin, and need a very strong material coupled with a proven plastic resin / aggregate mix that would bond to the exposed concrete wall.
The repair materials that needed to be installed were only about 4" wide (10cm) and about 12" (30 cm) deep. Very thin. A cementitious approach would not be very effective in this situation.
Drain plates that could not be removed were our clue as to concrete that was being forced away from the rabbit, and into the drain.
Doing our work safely in a live rail shop requires silica dust exposure control plan. That plan includes best-in-class vacuum systems.
We used all of our HEPA 11 vacuums with all hand tools. The vacuums were coupled with pre-separators to ensure that our employees as well as the employees of the Railway are protected from silica dust with maximum recovery. SureBond has probably the best floor prep and vacuum equipment in Canada, as we specialize in renovations. Renovations are much more demanding than new construction flooring work.
Just in case there are dust puffs, such as when we are lifting / removing the concrete debris and loading into our electric wheelbarrow, we utilize a high-volume air mover / dust sock....just in case.
All of our equipment gave the Railroad confidence that they were safe, especially with the Silica Dust Exposure Control Plan that we provided.
Our work areas were always taped to ensure that the employees were safe away from open drains while we performed our work. Again, we had no dust complaints from the Safety Committee or Management.
Our hand tools and vacuums in action performing the heavy demolition. No dust.
We also used HEPA 11 scrubbers should one of our tools not have a dust recovery port to a HEPA 11 vacuum.
There was a substantial amount of rubble removed.
Our backs were saved with this invaluable tool.
Demolition / removal continues.
Cribbing starts so that we can replace what we have removed. This includes adding rebar / ready-rod to strengthen the thin wall Silikal R17 concrete that we would be pouring into to bond to the steel walled rabbit channel that has been exposed.
Any concrete or rabbit steel exposed was prepared / primed with our Silikal(r) primer RU380 prior to pouring the R17 plastic concrete. The German railroad uses R17 for many decades for concrete repair of their assets.
Priming of the rough exposed concrete and exposed steel of the rabbit continues. The primer is fully cured in about 20 minutes.
Pouring R17 between the cribbing form and exposed rabbit steel / broken concrete begins.
The material is mixed and poured with aggregate. Within 1-1/2 hours maximum, the material was full strength of an estimated 85-90 MPa.
All Silikal(r) products are MMA (methyl methacrylate) based. They cure quickly. We have even done concrete repair at -25C of R17 with a special additive, and the concrete was fully cured in about 4 hours....with no heat supplied.
The finished SureBond Silikal(r) R17 is fully cured, and wall strengthened.
The new drain support rims now allow for the grates to be removed. Drainage was fully honored / restored.
We touched up some of the transitions between base slab and the R17 to ensure that there were no trip hazards.
Drain plates now fit back onto the new rim supports. Trip hazards were fixed. Client very happy! We turned over the finish product with instructions that all work was immediately available for FULL use.
PROJECT OBJECTIVE:
structural repair of concrete around car progression system.
RE-BUILD DRAIN WITH STRUCTURAL SUPPORT TO RE-INFORCE STABILITY OF THE RABBIT TRACK
AVOID TYPICAL CONCRETE REPAIR CURING TIME / MAXIMIZE RETURN TO SERVICE. USE BEST-IN-CLASS REPAIR MATERIALS
avoid costly downtime and cost of replacing rabbit car progression system
minimize downtime of track / NO BUSINESS IMPACT
FIX CONCRETE / TRIP HAZARDS