The need for sewer system rehabilitation is not restricted solely to sanitary sewer infrastructure. Admittedly, the environment in sanitary sewers can be very destructive because of both corrosion and physical abuse, particularly in older systems, and for these reasons the focus is typically, and understandably, on the sanitary side of sewer systems, as they can deteriorate rapidly if not maintained. However, storm sewer structures, particularly catch basins and storm sewer manholes, cannot be neglected. Almost all suffer from age and vehicular induced wear and tears, as most are located in roadways. In cold climes, freezing thaw cycles and snow plowing increase physical wear and abuse, and road salts and ice melt chemicals can be very corrosive to standard Portland cement-based structures and the mortar joints in brick structures.
Over the years, standard maintenance and repair of storm sewer structures involved frequently repairing damage with standard Portland cement-based repair mortars. However, these repairs were always temporary and failed over time, as standard repair mortars do not add any measurable strength or protection to the structures. At some point, such repairs become fruitless and failing structures must be completely replaced, which is always an expensive endeavor, with excavation, new paving and traffic interruptions involved.
However, there is an alternative to short-lived repairs that will substantially extend the service life of these structures and minimize costly replacement. Sauereisen’s Restokrete F-121 Substrate Resurfacer, in combination with their Sewergard 210 epoxy products, can rehabilitate and protect storm sewer catch basins and manholes. The F-121 Substrate Resurfacer is a high strength (7,000 plus psi compressive strength), rapid set repair mortar that will structurally repair a damaged catch basin or manhole. When applied to properly prepared surfaces, the F-121 will replace damaged concrete or missing brick and brick mortars, restoring the structure and adding considerable strength to the original construction. The F-121 can be troweled in place or applied by pumping and spraying. The use of reinforcing allows for thick applications where needed.
If the damage to the structure is simply due to aging or routine physical abuse, rehabilitation with the F-121 will restore the structure to its original condition, with enhanced strengths that will resist physical abuse, extending the service life of the structure indefinitely. If the damage to the structure was caused by corrosion, the Sauereisen Sewergard 210GL epoxy coating can be applied the next day over the F-121 by brush, roller or spray to provide complete chemical resistance to road salts and ice melt chemicals, eliminating corrosion damage and minimizing future repairs and replacements, while assuring overall asset longevity.
These exact restoration and protection procedures were successfully undertaken by a large northeastern municipality where several thousand catch basins and manholes were on a never-ending cycle of repair, with many eventually requiring costly replacement. Over the course of several years, over 600 structures were addressed with the Sauereisen system, with the majority only requiring the F-121 surface restoration. Where it was determined that corrosion was the cause of the damage to a structure, the Sewergard 210 epoxy was also used to provide an impermeable barrier over the restored surfaces that would resist corrosion and prevent future damage.
Restored structures were inspected periodically and found to be performing as intended, without the short cycle maintenance requirements that had been experienced in the past, and this approach to repairs became standard procedure for the municipality. This new repair procedure reduced the municipality’s overall storm sewer maintenance costs and minimized replacements, which typically cost the municipality 5-6 times what it cost to restore and protect the structures with the Sauereisen F-121/210GL system. The end result was less maintenance and lower storm sewer expenditures for the municipality.