Title:
Durability Study of 35 Year Old Post-Tensioned Bridge
Author(s):
Morris Schupack
Publication:
Concrete International
Volume:
16
Issue:
2
Appears on pages(s):
54-58
Keywords:
bridges (structures); corrosion resistance; demolition; evaluation; post-tensioning; prestressing steels; General
DOI:
Date:
2/1/1994
Abstract:
The 14-span, 120-ft (36.6-m) Bissell Bridge constructed in 1957 was a cast-in-place, novel, post-tensioned bridge. Its planned demolition provided the opportunity to evaluate the durability of various material and construction features. Findings indicate that those portions of the superstructure that were constructed complying with most of the then-current standards behaved well and had good durability. The 35-year-old bridge slab was in excellent condition with minimal chloride ion ingress. Observed distress related mainly to poorly grouted or never grouted tendons. In spans where highly chloride-contaminated tendon grout was used, major tendon corrosion occurred. Tendon corrosion and the difficulty in diagnosing the same from external evidence are discussed. Observations and findings, as well as recommendations for durable details, are presented.