Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: David W. Fowler
Publisher: Transportation Research Board
ISBN: 0309143543
Category : Technology & Engineering
Languages : en
Pages : 75

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Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 423: Long-Term Performance of Polymer Concrete for Bridge Decks addresses a number of topics related to thin polymer overlays (TPOs). Those topics include previous research, specifications, and procedures on TPOs; performance of TPOs based on field applications; the primary factors that influence TPO performance; current construction guidelines for TPOs related to surface preparation, mixing and placement, consolidation, finishing, and curing; repair procedures; factors that influence the performance of overlays, including life-cycle cost, benefits and costs, bridge deck condition, service life extension, and performance; and successes and failures of TPOs, including reasons for both.

Author: Andrew Joseph Shearrer
Publisher:
ISBN:
Category : Concrete
Languages : en
Pages : 200

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Epoxy polymer overlays have been used for decades on existing bridge decks to protect the deck and extend its service life. The polymer overlay's ability to seal a bridge deck is now being specified for new construction. Questions exist about the amount of drying time needed to achieve an acceptable concrete moisture content to ensure an adequate bond to the polymer overlay. The 2007 Kansas Department of Transportation (KDOT) specifications for new bridge decks call for a 14-day wet curing period followed by 21 days of drying. If not enough drying is provided, the moisture within the concrete can form water vapor pressure at the overlay interface and induce delamination. If too much drying time is provided, projects are delayed, which can increase the total project cost or even delay overlay placement until the next spring. A testing procedure was developed to simulate a bridge deck in order to test the concrete moisture content and bonding strength of the overlay. Concrete slabs were cast to test typical concrete and curing conditions for a new bridge deck. Three concrete mixtures were tested to see what effect the water-cement ratio and the addition of fly ash might have on the overlay bond strength. Wet curing occurred at three different temperatures (40 degrees F, 73 degrees F, and 100 degrees F) to see if temperature played a part in the bond strength as well. The concrete was then allowed to dry for 3, 7, 14, or 21 days. Five epoxy-polymer overlay systems that had been preapproved by KDOT were each used in conjunction with the previously mentioned concrete and curing conditions. After this, the slabs were setup to perform pull-off tests to test the tensile rupture strength. The concrete slabs with the different epoxy overlays were heated to 122-125 degrees F to replicate summer bridge deck temperatures. Half of the pull-off tests were performed when the slabs were heated and half were performed once the slabs had cooled back down to 73 degrees F plus or minus 5 degrees F. Results from the pull-off tests as well as results from a moisture meter taken on the concrete prior to the overlay placement were compared and analyzed. Testing conditions were compared with each other to see which had a larger effect on the epoxy polymer overlay's bond strength. The results showed that concrete bridge deck polymer overlays could be placed sooner than 21 days after concrete placement and still have an adequate bond.

Author: Stella Marusin
Publisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 216

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Author: Timothy L. Ramirez
Publisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 134

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Author: Timothy L. Ramirez
Publisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 70

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Book Description
The purpose of this study is to evaluate the application of FLEXOGRID, a modified epoxy resin, to a concrete bridge deck. The FLEXOGRID is designed to impart a thin, fast curing, water impermeable protective overlay to the deck. The FLEXOGRID is 1/4 inch thick consisting of 2 applications of an epoxy broadcasted with a hard aggregate. The FLEXOGRID was easy to apply after the bridge deck delaminations were repaired and the entire deck was shotblasted. Only minor application problems occurred which can be corrected for future applications.

Author: Oregon. State Highway Division
Publisher:
ISBN:
Category : Polymer-impregnated concrete
Languages : en
Pages : 30

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Book Description
This report describes work done on various combinations of monomers and polymer concrete mixes and identifies the mixes showing the greatest potential for use in bridge deck overlays. Presented are test results showing physical properties of various polymer concrete mixes, such as compressive strength, split tensile strength, modulus of elasticity, thermal coefficient of expansion, and shrinkage coefficient. The effects of polymer content, work time, and temperature on various properties are also discussed. The development of two polymer concrete systems with excellent membrane potential are described along with the details of bonding characteristics of several systems. Finally, a polymer concrete mix with suitable properties for deck and pavement patching is detailed.

Author: Andrew Joseph Shearrer
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Epoxy polymer overlays have been used for decades on existing bridge decks to protect the deck and extend its service life. The polymer overlay's ability to seal a bridge deck is now being specified for new construction. Questions exist about the amount of drying time needed to achieve an acceptable concrete moisture content to ensure an adequate bond to the polymer overlay. Current Kansas Department of Transportation (KDOT) specifications for new bridge decks call a 14 day wet curing period followed by 21 days of drying (Kansas DOT, 2007) If not enough drying is provided, the moisture within the concrete can form water vapor pressure at the overlay interface and induce delamination. If too much drying time is provided projects are delayed, which can increase the total project cost or even delay overlay placement until the next spring. A testing procedure was developed to simulate a bridge deck in order to test the concrete moisture content and bonding strength of the overlay. Concrete slabs were cast to test typical concrete and curing conditions for a new bridge deck. Three concrete mixtures were tested to see what effect the water -cement ratio and the addition of fly ash might have on the overlay bond strength. Wet curing occurred at 3 different temperatures (40°F, 73°F, and 100°F) to see if temperature played a part in the bond strength as well. The concrete was then allowed to dry for 3, 7, 14, or 21 days. Five epoxy-polymer overlay systems that had been preapproved by KDOT were each used in conjunction with the previously mentioned concrete and curing conditions. After, the slabs were setup to perform pull-off tests to test the tensile rupture strength. The concrete slabs with the different epoxy overlays were heated to 122-125°F to replicate summer bridge deck temperatures. Half of the pull-off tests were performed when the slabs were heated and half were performed once the slabs had cooled back down to 73°±5°F. Results from the pull-off tests as well as results from a moisture meter taken on the concrete prior to the overlay placement were compared and analyzed. Testing conditions were compared with each other to see which had a larger effect on the epoxy polymer overlay's bond strength.

Author: David W. Fowler
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 222

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Author: Michael M. Sprinkel
Publisher: Strategic Highway Research Program (Shrp)
ISBN:
Category : Concrete bridges
Languages : en
Pages : 124

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Book Description
This report presents the rapid methods used by state highway agencies for the protection, repair and rehabilitation of bridge decks. The report is based on a review of the literature; the responses to questionnaires sent to state departments of transportation, Canadian provinces, selected turnpike and thruway authorities, technology transfer centers, and material suppliers; and the evaluation of 50 bridge decks located in seven states. Polymer overlays, sealers, high-early strength hydraulic cement concrete overlays, and patches are compared for their performance characteristics and service life.