The care and maintenance of infrastructure has become a global issue. One of the most critical areas of concern is wastewater piping and related structures. It is well known that corrugated metal pipes used in storm-water structures are corroding and microbial-induced-corrosion of sanitary sewers of various materials results in structural concern. Geopolymers have long been known to provide enhanced physical performance to traditional cementitious binders with the added advantages of significantly reduced greenhouse emissions and superior chemical resistance. Geopolymers are ceramic polymer technology that creates a chemical material similar to natural stone that is superior to traditional Portland cement and shotcrete materials. However, they have not generally been contractor-friendly.
This paper reviews a geopolymer mortar system that has been used in the U.S. since 2011 is gaining use in additional global markets for trenchless pipe rehabilitation. The system is spray cast either by rotary nozzle or via traditional shotcrete delivery systems inside of existing structures to create whole new structures which do not depend on the existing structure, just using it as formwork. This paper discusses competitive advantages over other trenchless repair solutions such as spiral wound, slip-lining and CIPP through specific case studies including a corrugated metal storm drain rehabilitation in Hidalgo, Texas along with the repair of a concrete storm sewer in Hong Kong