Assessing Manhole Rehabilitation Options

No one knows how many manholes dot U.S. streets and roads, but most of them could probably use some sort of repair. And there are lots of ways to do that. The challenge when parsing vendor claims about a material, process, and/or product is that no American Society for Testing and Materials (ASTM) International standard exists. Nor is there an industry-accepted definition of “structural” repair. There’s nothing authoritative to refer to.

The Water Environment Research Foundation has spent more than $200,000 over the last few years to fill in those gaps. Researchers looked at research other researchers had done and pulled together managers from 31 utilities nationwide for a workshop. Then they subjected 24-inch concrete cylinders lined with composites, epoxies, inserts, and mortars to ASTM C-497 (the “D-load” test). They used those findings to project results for various manhole condition and loading scenarios.

The result is a FREE Access-based software tool you can use to choose the appropriate methodology for your agency’s needs and budget. It won’t tell you what vendor to use, but it will save time by immediately eliminating options that are too expensive or unnecessary. You’ll be asked to input data on manhole condition, soil conditions, groundwater table and characteristics, site-specific loads, and location (i.e., high, low, or no traffic). The tool processes the information to recommend structural class A, B, or C (see chart below) and installation method (no-dig, low-dig, or open-cut).

P.S. Most manhole rehabilitation methods being applied today are semi-structural. To download the tool, e-mail Walter Graf at wgraf@werf.org or Firat Sever at fsever@structurepoint.com.