Over the past few years the Technology and Development Department of Consumers Gas has been working to develop less intrusive repair technologies and improved reinstatement techniques. In recent years, the development of "keyhole" technology has provided a viable alternative. Keyhole technology involves advancing a small hole to access the pipe or service and then using specially developed remote access tools operated from road surface for the repair. Thus the need for workers to enter the excavation is avoided. This technology is particularly applicable to gas line servicing and maintenance. To enhance the cost effectiveness and efficiency of keyhole technology, the current research is aimed reusing the 450 mm pavement is aimed reusing the 450 mm pavement core to effect permanent reinstatement of the pavement by the utility crew, immediately following repairs. Equipment and procedures have been developed which permit the pavement core to be reinstalled and bonded in place using a modified methacrylate grout injected through the centre pilot hole. The grout is flowable, non-shrink and fast setting and allows the road to be opened to traffic within two hours of pavement reinstatement. Laboratory trials have been carried out which indicate that the bond strength obtained between the core and the original concrete is sufficient to carry maximum tire loads without the benefit of the underlying backfill support. Full scale field trials are currently underway to monitor the performance with time of the reinstated pavement under normal traffic loading. (A)
Samenvatting