There should be a change to ASTM C 31 that all cylinders be required to be cured immersed in water for the first 24 hours, and here's why.
After attending a whitetopping demonstration in Albuquerque in the fall of 2001 and then carefully reviewing the procedure, Max Bighorse, P.E., the Navajo Housing Authority design group’s civil engineer, decided to give whitetopping a try.
The ideal way to work safely on any jobsite is to identify and locate the existing underground utility lines before beginning any site excavation. In the real world, though, existing site conditions aren't always clear, and as-built drawings may not be accurate or updated to reflect site utility modifications. Using colored flowable fill to backfill utility lines provides excavation crews with a reliable and clear visual warning of potential hazards.
Late in the fall of 1999, Ft. Defiance, Ariz., became the first town in Navajo Nation to replace potholed asphalt streets with concrete. The project was so successful that several other towns in the reservation are following Ft. Defiance's example. Navajo Nation is the largest Indian reservation in the United States, covering more than 25,000 square miles and encompassing portions of Arizona, New Mexico, and Utah. The Navajo Housing Authority decided to switch from asphalt to concrete after hearing Ft. Defiance residents complain about all the potholes in their existing asphalt roadways. A key reason for NHA's decision was the good performance of concrete pavements installed 13 years earlier in other residential areas on the reservation. Although the pavements had cracked in many places, the wearing surfaces were intact.
