Grant: Alliance Grants

Sewerage is the civic infrastructure that transports sewage using concrete sewer pipes. Thousands of such sewerage pipe segments are replaced prematurely because of severe bio-corrosion caused by a prolonged exposure of concrete to highly corrosive, bacteria-laden, sewer environments. Maintaining and repairing aged and deteriorated sewerage infrastructure is an ongoing challenge for many municipalities and regional utilities, including Metro Vancouver. This is further complicated by the fact that aging sewerage infrastructure is often located under crowded urban areas, necessitating careful planning for assessment, repair, and replacement. With rapidly aging civic infrastructure in Canada, this problem is expected to only get worse. The applicants have recently developed, tested and patented a low-carbon, Multiphase Composite Coating (MCC) which when applied as a coating prevents bio-corrosion in sewer pipes. MCC is based on a modified geopolymer matrix of alumina silicate and magnesium phosphate with antibacterial agents encapsulated in it. The CO2 equivalent emissions from the MCC are estimated to be 65%-85% less than that of traditional Portland cement mortars. The coating has already been hand-applied to a sewerage chamber in Vancouver. Here, it is proposed to improve the MCC by further reducing its carbon footprint by using CO2 sequestered recycled sand, employing natural biocides and reinforcing it with recycled fiber. Rheology will be studied so MCC can be spray applied using robotics based on Artificial Intelligence (AI). Modified MCC will be spray applied on Metro Vancouver's assets using sensors to monitor performance. The Multiphase Composite Coating (MCC) will not only be useful as a spray-applied liner for the rehabilitation of existing pipes, manholes and chambers, but also for new precast pipes and manholes. Full-scale trials with Metro Vancouver will help improve the MCC technology and reduce both materials and placement costs. The project will provide the two private companies a major competitive edge in the burgeoning international infrastructure rehab market.