Q: We are retrofitting a highway edge drain where rubberized concrete was used as the base course layer. What type of geotextile or geosynthetic should we consider for this project’s drain?
A: Clogging of geotextiles, geonets, geopipe and/or geocomposites is a challenging design for certain soil types or unusual situations. This is one of them. I would strongly recommend a paper by Aiyoub Abbaspour and Burak Tanyu from George Mason University on the subject, “Chemical Clogging and Geotextile Serviceability in Subdrains Adjacent to Recycled Concrete.” The issue is precipitate clogging and requires a very open system utilizing geotextiles with an Apparent Opening Size (AOS) of #30-40, Percent Open Area (POA of >35%. Generally, woven monofilaments are used in such cases.
Abbaspour, A., and Tanyu, B. (2021). “Chemical clogging and geotextile serviceability in subdrains adjacent to recycled concrete.” Geosynthetics International 28(4):1–44.