Deflection Testing
Concrete pipe carries most of the soil and live load, therefore a structural test of the pipe is performed at the plant in a three-edge bearing test as per ASTM C497, confirming strength. A deflection test of concrete pipe is not applicable. Plastic pipe relies primarily on the soil envelope that is built around the pipe in the field by the contractor. Deflection testing of the pipe is needed, after back fill is completed to confirm the structural integrity of the installation.