Section 4148. Drain Tiles
For concrete drain tile meet the requirements of AASHTO M 178 or ASTM C 412, standard quality, extra quality, or special quality, as specified, or for clay drain tile meet ASTM C 4, standard, extra quality, or heavy duty, as specified. When the quality is not specified, use extra quality tile in roadway embankments, and use standard or standard quality tile in other locations.