Our colleagues in the USA have submitted samples to ASSHTO (the American Association of State Highways and Transportation Officials) to evaluate Capiphon for use on their roads and highways. See their website at
The list of tests for the product included: thickness: width: hardness: impact resistance: tensile properties: brittleness: cellular plastic compressive properties: and water permeability in 3 different conditions
Some tests have no relevance for everyday use – breaking strain and brittleness at -29 degrees Centigrade, for example – but others showed some important characteristics such as
- There was no distortion of the Capiphon under pressure.
- There was no evidence of intrusion into the drain system by the soil (a sandy clay) even under load.
- The flow rate is proportional to hydraulic gradient indicating the added stress does not significantly change the transmissivity of the material.
In all, the Capiphon Drain belt is recommended for highway subsurface drainage as part of a multidisciplinary approach to solving groundwater problems responsible for pavement failures and slope failures.
A good result! The final report has been uploaded to our website – see