The test scores are in and concrete slabs for highway repairs get an A plus grade from the Ministry of Transportation Ontario.
Never one to rush into any new technology, the MTO ran its first test of precast concrete slab repair on concrete pavements in 2004. That trial on Highway 427 in Toronto led to a specification and more precast repair work resulted.At every step, the slabs have been a success leading to a pilot using precast concrete slabs to repair flexible pavement in a fall 2016 trial.
The results are positive: It costs more but there are savings in reduced traffic disruption and extended pavement life which more than offset the initial installation cost.“We were not surprised by the findings,” says Stephen Lee, head of the MTO’s pavements and foundations section, materials engineering and research office. “And we will continue to monitor the long-term performance of this pilot.”
These slab repairs seem best suited for heavy truck traffic on asphalt pavements with 300 mm or more thickness but with more than 25,000 trucks per day which inevitably lead to rutting and premature deterioration.
Shave and pave, the standard treatment, only extends the pavement lifecycle three to five years. It’s far short of the eight to 12 years needed before the rutting, cracking and overall deterioration returns.