Tag
#prestressing
2 topics across all disciplines.
Prestressed and post-tensioned concrete
Why concrete is squeezed before it is loaded, the difference between pre-tensioning in a casting yard and post-tensioning on site, how losses eat a third of the force you paid for, and why a grout void inside a duct is the most dangerous defect in modern bridge engineering.
Post-tensioned containment walls
An LNG outer tank wall has to hold a column of liquid against hoop tension that ordinary reinforced concrete would crack under. Prestressing puts the wall into permanent compression so it never cracks through, and the whole design turns on keeping that compression for forty years.