Sealing of Cracks on Florida Bridge Decks with Steel Girders

Sealing of Cracks on Florida Bridge Decks with Steel Girders
Author: Adel ElSafty
Publisher:
Total Pages: 182
Release: 2012
Genre: Concrete bridges
ISBN:

One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.

Development and Layout of a Protocol for the Field Performance of Concrete Deck and Crack Sealants

Development and Layout of a Protocol for the Field Performance of Concrete Deck and Crack Sealants
Author: José Antonio Pincheira
Publisher:
Total Pages: 62
Release: 2009
Genre: Concrete bridges
ISBN:

The main objective of this project was to develop and layout a protocol for the long-term monitoring and assessment of the performance of concrete deck and crack sealants in the field. To accomplish this goal, a total of six bridge decks were chosen for study. The decks have ages that vary from 4 to 30 years old, are all in good condition, though some presented a variety of longitudinal, transverse and diagonal cracking. In each deck, test segments were laid out along one lane in four of the six bridges. Drill powder samples were extracted in each segment in order to determine the in-situ, near-surface chloride ion content of the deck. Laboratory analyses of the samples showed that the chloride ion content varied between 3.2 lb/cy for the younger decks (3 years old) and 20.8 lb/cy for the older decks (28 years old). Based on the recommendations of a previous laboratory investigation, a pool of the best performing deck and crack sealants were selected to be applied in the decks. In two bridges, deck segments were sealed with four deck sealants while one segment was left unsealed to be used as a control segment. Additionally, the cracks in each of these segments were sealed with five crack sealants. While two other decks were also scheduled for sealing as part of this phase of the project, they were not done because the required curing time for some of the products was longer than deemed acceptable by DOT crews for these high traffic bridges. It is recommended, however, that every effort be made to have these decks be sealed in the near future. The remaining two bridges had been sealed at the time of construction. While no specific information could be secured about the product used in these decks, the low chloride ion content in these decks suggested that the applied product has helped reduce the ingress of chloride ions. Therefore, it is recommended that these decks continue to be monitored over time. Based on the inspections and the data collected in the field, a protocol and schedule for the continuing monitoring of sealant performance is presented.

Control of Cracking in Bridge Decks

Control of Cracking in Bridge Decks
Author: D. Darwin
Publisher:
Total Pages: 7
Release: 2004
Genre: Bridge decks
ISBN:

Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges--bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks with silica fume and conventional concrete overlays. The study demonstrates that crack density increases as a function of cement and water content, and concrete strength. In addition, crack density is higher in the end spans of decks that are integral with the abutments than decks with pin-ended supports. Most cracking occurs early in the life of a bridge deck, but continues to increase over time. This is true for bridges cast in both the 1980s and the 1990s. A key observation, however, is that bridge decks cast in the 1980s exhibit less cracking than those in the 1990s, even with the increase in crack density over time. Changes in materials, primarily cement fineness, and construction procedures over the past 20 years, are discussed in light of these observations. A major bright spot has been the positive effect of efforts to limit early evaporation, suggesting that the early initiation of curing procedures will help reduce cracking in bridge decks.

Bridge Inspection and Rehabilitation

Bridge Inspection and Rehabilitation
Author: Parsons Brinckerhoff
Publisher: John Wiley & Sons
Total Pages: 309
Release: 1993-01-12
Genre: Technology & Engineering
ISBN: 0471532622

More than a third of America's bridges are considered substandard--either structurally deficient, functionally obsolete or both. Offers first-rate, practical guidance regarding the inspection and rehabilitation of aging bridge infrastructure including all elements involving structure, various materials and design types. Features seismic retrofit and coverage of environmental issues. Each chapter is written by an authority on the subject. Contains top-quality, detailed line illustrations plus photographs of actual rehab projects.

Effectiveness and Performance of Crack Sealants for Bridge Decks

Effectiveness and Performance of Crack Sealants for Bridge Decks
Author: José A. Pincheira
Publisher:
Total Pages: 38
Release: 2009
Genre: Concrete
ISBN:

The primary objective of this study was to assess the effectiveness and performance of selected products for sealing cracks in concrete bridge decks. The project was a follow up study of an earlier investigation to expand the selection of crack sealers for use in the field. A total of nine crack sealants were tested in this study under laboratory conditions that simulated the exposure to deicing salts and freeze?thaw cycles encountered in practice. Five of the products had been tested earlier under the same laboratory conditions but for a limited range of crack widths. Four additional products were also included in this study. Based on the test results, the performance of the sealants was evaluated and ranked, and recommendations for their use in the field are provided.