Details:

Creators:
Busba, E. ; Sagues, A. ; Mullins, G.
Busba, E. ; Sagues, A. ; Mullins, G. Less -
Corporate Creators:
University of South Florida. Department of Civil and Environmental Engineering
Corporate Contributors:
Florida. Department of Transportation
Subject/TRT Terms:
[+]
Autogenous Healing Concrete Corrosion Cracking Cracks Pipe Reinforced Concrete Reinforced Concrete Pipe Reinforcing Steel
Resource Type:
Tech Report
Geographical Coverage:
Florida
Edition:
Final report; 07/01/2009-7/1/2011.
Corporate Publisher:
University of South Florida. Department of Civil and Environmental Engineering
Abstract:
Inspection of recently placed reinforced concrete pipes often reveals cracks. Florida DOT was in

need of in-place crack acceptance criteria. This project was intended to determine the influential parameters

responsible for crack healing in in-place Reinforced Concrete Pipes (RCP), determine what maximum crack

width was amenable to autogenous healing and sufficient to mitigate reinforcement corrosion, and formulate

guideline models for pipe crack acceptance criteria during construction. A literature survey indicated a

reasonable expectation for autogenous healing to eventually occur for cracks narrower than about 0.020 inch.

The prognosis was less favorable for wider cracks, and there was little assurance that autogenous healing would

reliably take place for crack widths exceeding about 0.100 inch. Laboratory experiments did not produce

significant autogenous healing of 0.100-inch or 0.020-inch-wide cracks in reinforced concrete pipe specimens

over an approximately 2-month-long period. Corrosion tests showed that significant reinforcement wire corrosion

could take place in a short time in reinforced concrete pipe with 0.100-inch-wide cracks, and that corrosion

damage was considerably slower when the cracks were 0.020 inch wide. Corrosion was aggravated by the

presence of moderate chloride ion contamination (500 ppm), but active steel corrosion occurred even without it.

A predictive model for corrosion development in cracked reinforced concrete showed for 500 ppm chloride very

short durability projections for the 0.100-inch-wide crack condition, and moderately strong to little limitation in

durability for the 0.020-inch-wide crack cases. Acceptable crack width guideline models proposed for discussion

included a restrictive alternative, with 0.020 inch width allowable only for environmental chloride no greater than

500 ppm; a less restricted alternative allowing 0.020 inch up to 2000 ppm chloride; and a sliding option for up to

2000 ppm chloride where pipe service life was progressively derated to zero for crack widths increasing from

0.020 inch to 0.100 inch. In all models the acceptable width defaulted to 0.010 inch if the other conditions were

not met.


Format:
PDF
Funding:
BDK84 977-06
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:13d539ae3e40c2670461345c61ac73332782ae4bd7275312b360abafc973e96e
Download URL:
https://rosap.ntl.bts.gov/view/dot/22407/dot_22407_DS1.pdf
File Type:

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