Use of Innovative Pre-Cast Concrete Slab Repair Technology in Canada

Abstract

\In 2004, the Ministry of Transportation Ontario (MTO) carried out a trial project to evaluate construction techniques for pre-cast concrete slab repairs in concrete pavement. The trial was carried out on Highway 427, a heavily trafficked freeway in Toronto, Canada. The trial project required demonstrations of three pre-cast concrete pavement full-depth repair methods: the Fort Miller Super-SlabTM Intermittent Method, the Fort Miller Super-SlabTM Continuous Method, and the Michigan Method. Each method involves designing and fabricating pre-cast concrete slabs to replace deteriorated concrete pavement. The methods differ in how the base is prepared and how the pre-cast slab is installed and dowelled to the existing concrete pavement. Non-destructive testing using a Falling Weight Deflectometer (FWD) was undertaken after construction to assess load transfer efficiency (LTE) and to detect loss of support underneath the pre-cast slab. Details of the methodologies, site conditions, contract specifications, construction and FWD analysis are presented. This is the first construction experience in Canada with innovative pre-cast concrete slab repairs for concrete pavements. MTO will continue to monitor the field performance of these technologies and assess the cost effectiveness of this alternative to full-depth fast-track concrete repairs.