In late 2017, the MTO (Ministry of Transportation of Ontario) had approved the use of KING RS-S10 concrete for small patch repairs on highways and bridges in Ontario. On November 28, 2017 the material was put to the test for the first time on an emergency repair, which was located on the QEW (Queen Elizabeth Way) highway westbound lanes by Mississauga’s Credit River. The contractor was required to remove damaged material, prepare the surface, and have new material installed, in order to reopen the lanes for morning traffic.
The work entailed closing a live line around 10 PM, to begin demolition on the first patch. Once the first patch was uncovered and the surface was prepared with abrasive sandblasting, an additional mid-lane was closed to begin demolition for the second repair. It was approximately midnight when the contractor began mixing the RS-S10 for the first repair. RS-S10 was mixed, 3 to 4 bags at a time, in a portable drum-mixer. The first repair patch used approximately 0.35 m3 (12.4 ft3) of RS-S10.
Since ambient temperatures were slightly below 5 °C (40 °F), the contractor used tarped forms and construction heaters to ensure that the concrete was at a proper curing temperature. By heating the area around the concrete, workers were able to ensure that the repair achieved 25 MPa (3625 psi) or higher at 3 hours.
By the time the concrete had been poured into the first patch, the second patch was ready to receive material. The second repair area required approximately 0.10 m3 (3.53 ft3) of material, mixed in the same fashion as for the first repair. Once the second pour was completed, it was also covered with tarped forms and heated to ensure that the proper strengths were achieved.
3 hours later, around 4 AM, the material had achieved its appropriate strength of 25 MPa (3625 psi) or higher and was ready to receive its asphalt top-coat. Before the asphalt was applied, a primer was used to seal the concrete from evaporation and off-gassing. A hot-mix asphalt was applied, allowed to harden and cool, before the live lanes of traffic were opened around 7 AM.