We, the bridge maintenance engineersWe, the bridge maintenance … · 2012-11-01 · of New York...
Transcript of We, the bridge maintenance engineersWe, the bridge maintenance … · 2012-11-01 · of New York...
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We, the bridge maintenance engineersWe, the bridge maintenance engineersWe, the bridge maintenance engineers We, the bridge maintenance engineers of New York hold these truths to be selfof New York hold these truths to be self--
evident: all joints leak, all concreteevident: all joints leak, all concreteevident: all joints leak, all concrete evident: all joints leak, all concrete cracks, and rust never sleeps. We will cracks, and rust never sleeps. We will
strive to capitalize our way out of strive to capitalize our way out of st e to cap ta e ou ay out ost e to cap ta e ou ay out omaintenance and maintain our way out maintenance and maintain our way out of capital. It is our endeavor to educate of capital. It is our endeavor to educate o cap ta t s ou e dea o to educateo cap ta t s ou e dea o to educateothers that a bridge is as important to a others that a bridge is as important to a
highway as a diamond is to a ring.highway as a diamond is to a ring.g y gg y g
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OBJECTIVESOBJECTIVES
FOCUS AREASFOCUS AREASDeck TreatmentsGirder Ends
Spot PaintingSpot PaintingBearing Replacement
Small Movement Expansion JointsSmall Movement Expansion Joints
EVOLVING PRACTICESEVOLVING PRACTICES
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DECK TREATMENTSDECK TREATMENTSSheet MembranesSheet Membranes
NCHRP Synthesis 425completedcompleted
PolymersNCHRP Synthesis 423NCHRP Synthesis 423
completed
Paver-Placed SurfacePaver Placed Surface TreatmentsNCHRP 20 7 Task 330NCHRP 20-7 Task 330
on-going
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RESEARCH - SYNTHESISRESEARCH SYNTHESIS
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SHEET MEMBRANESSHEET MEMBRANESNCHRP Synthesis 425y
Bond–Bond-BondHot appliedot app ed
Crack treatments – rubber mat or geo grid
Worksite- require protection boardNeed – specifications based on quantitative definition of performance requirementsperformance requirements, objective testing, & LCC.
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Waterproofing Bridge Deck Hot Mix Asphalt Overlay
ITEM 402.97
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HYDROMILLING with LATEX or POLYESTER
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TREATMENT SELECTIONDecks are rated 5
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GIRDER ENDSGIRDER ENDS
BANG for the BUCK• High 4 vs. Low 5g• First Preservation $
GSFLAGS• Section Loss• Cracks
Frozen BearingsOut of plane bending
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80
Reporting Numbers
3040506070
01020
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
YearRed Yellow Safety
R ti Fl d C diti
150200250
Reporting Flagged Condition
050
100
TOTAL
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BEARING REPLACEMENTBEARING REPLACEMENT
Elastomeric onElastomeric on Concrete
AASHTO D t ilAASHTO DetailAllows elimination of masonry platemasonry plateIncludes keepersMathCad Module
AccessMoog trailersMoog trailers
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MAINTENANCE of COATINGSMAINTENANCE of COATINGSSurface Prep TrialsSurface Prep Trials
SP-3High pressure washHigh pressure wash
Materials TrialsFi ld & l b t i lField & lab trials1 component
Other States PracticesResearch
NCHRP 14-30
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EXPANSION JOINTSEXPANSION JOINTS
Failure MechanismsFailure MechanismsElastomeric concrete
Unsound concreteImproper mixing Open too soon
Seal / Joint / GlandImproper sizingSloppy workmanshipSloppy workmanship
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NYSDOT Joint Calculator
1. Why is the Calculator needed?y2. What does the Calculator do?3 C ?3. How does the Calculator work?
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To address Joint Seal failures across the State.
Possible reasons for failure include:1. Not choosing the correct width of the joint seal g j
during installation.2. Bad workmanship during installation of the p g
joint seal.
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We basically use one of two methods:1 Research Record Plans in the office prior to1. Research Record Plans in the office prior to
going on-site, find the Design Opening with Design Temperature in the plans then refer toDesign Temperature in the plans, then refer to Manufacturer specifications and sizes (correct approach).
2. Measure the existing joint opening and refer to Manufacturer specifications and sizes (incorrect approach).
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1 R d Pl R h1. Record Plan Research
Record Plans often have a detail and a table which indicate the design joint opening at 68oF.With this information, you can use the Manufacturer tables. The Manufacturer tables h i t f d i j i t i lshow a variety of design joint openings along
with wider recommended joint seal widths (sometimes with a different design temp i e(sometimes with a different design temp i.e. 60oF).
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From Record Plans
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Manufacturer Specificationsp
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Closed-cell Foam JointsClosed cell Foam Joints
Closed-cell foam joint seals have become aClosed cell foam joint seals have become a popular choice of material to use when replacing armorless joint seals. This material behaves well i i b t t ll i t i Thi iin compression but not as well in tension. This is reflected in the Manufacturer’s Specifications which typically state Max Compression is 60%,which typically state Max Compression is 60%, Max Tension is 30%.
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2. Manufacturer Specifications
Just go out to the bridge, measure the joint opening to work on and refer to the Manufacturer’s table.
– Not a good idea –The temperature of the bridge that day probably isn’t 68oF.
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1 Why is the Joint Calculator Needed?1. Why is the Joint Calculator Needed?
ProblemsThe tables included in the Manufacturer Specifications indicate recommended seal widths based on a Design Temperature (i.e. 60oF)
You need to know the Design Joint Opening at the Design Temperature from Record Plans to use the Manufacturer t bl Thi i f ti i t l i th R d Pltables. This information is not always in the Record Plans, and when it is, it can be time consuming to find it. We sometimes don’t do it.
Also, if the joint opening was somehow modified after the original construction, the record plans are of no use.
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1. Why is the Joint Calculator Needed?
ProblemsThe tables included in the Manufacturer Specifications indicate recommended seal widths to use for a variety of ybridge joint openings that allow the seal material to experience both compression and tension.
We don’t want the joint material to experience tension, we want zero tension.
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Bridge Maintenance Charge:
Develop a calculator for Bridge Maintenance staff th t d t i th i j i t l tthat determines the proper size joint seal to install at any given temperature while on-site. The seal installed should not be subjected toThe seal installed should not be subjected to tension throughout its useful life.
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2 Wh t d th J i t C l l t D ?2. What does the Joint Calculator Do?1. Calculates the Total joint movement in inches for the full range of1. Calculates the Total joint movement in inches for the full range of
temperatures established for each Region by AASHTO. In other words: it calculates the distance the girder expands from the lowest to the highest temperatures within a DOT Region.
2. Calculates “expected” joint widths or openings at three different temperatures (coldest temp, 68oF, warmest temp.)
3. Calculates the proper width and depth of the closed-cell foam3. Calculates the proper width and depth of the closed cell foam material to install on repair day while the crews are on-site. Sizing the joint material to equal the gap at the coldest temperature would not put the material into tension.
4. Calculates the Max. compression of the closed-cell foam material at the warmest temperature to see if it exceeds Manufacturer Max. Compression limit (typically 60%).
5. It does all this based on inputs from field observations.
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3 How does the Joint Calculator Work?3. How does the Joint Calculator Work?
Basically comes down to calculating movement ofBasically comes down to calculating movement of the bridge as temperature changes.
N d 3 i bl t l l t “T t l M t”Need 3 variables to calculate “Total Movement”1. Coefficient of Thermal Expansion. “Φ”
2. Temperature Range (Max & Min) for your2. Temperature Range (Max & Min) for your particular Region. “∆T”
3. Length of bridge beams “contributing” to the total movement in the joint “L”total movement in the joint. L
Total Movement = Φ x ∆T x L
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NYSDOT E i J i t C l l tNYSDOT Expansion Joint Calculator
M k l i f h f ll i iMake selections for the following categories:
NYSDOT Region R7
Primary Member Type SteelPrimary Member Type Steel
Input values for the following categories:Input values for the following categories:
Exist Temperature of Primary Member 55oF
*Length of Member(s) contributing to total movement @ joint 124Feet
*Exist Joint Opening (perpendicular to header) ⊥ 2inches
*Skew Angle (0o≤ θ <90o) 18Degree Skew
Max. Compression limit % of joint material (from Manufacturer) 60%
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Results: (Perpendicular to header)
Joint Opening at 68oF (⊥) 1.88inches
Joint Opening at Coldest oF (⊥) 2.69inches
Joint Opening at Warmest oF (⊥) 1.54inches
Total movement of Joint within full Temp range (⊥) 1.15inchesTotal movement of Joint within full Temp range (⊥) 1.15inches
Width of New Closed Cell Foam (use Coldest Temp width (⊥)) 2.69inches
Depth of New Closed Cell Foam (if Manuf. info. not available) 2.50inches
Acceptablility based on Manufacturer's Compression limit OK
Compression @ Warmest Temp 42.75%
Compression @ Exist Temp 25.65%
Results: (Parallel to primary member)
Joint Opening at 68oF (//) 1.98inches
Joint Opening at Coldest oF (//) 2.83inches
J i O i W F (//) 1 62i hJoint Opening at Warmest oF (//) 1.62inches
Total movement of Joint within full Temp range (//) 1.21inches
Procedure B Temperature Ranges ‐ AASHTO
Coldest Temp for Primary Member used in your Region ‐20oF
Warmest Temp for Primary Member used in your Region +105oF
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Show Calculator
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Summary of ExamplesJt Size, Temp, Span L NYSDOT
Calculator(0% tension)
Manufacturer Recommendation
Conclusion
y p
2 ½”, 60oF, L=130 ft 3.31” (same) 3.25” Manufacturer recommendation same as NYSDOT calculator.
2 ½”, 10oF, L=130 ft 2.80” (-1/2”) 3.25” Manufacturer recommendation is oversized. May fail at high temps.
2 ½”, 100oF, L=130 ft 3.72” (+1/2”) 3.25” (t i 14 5%)
Manufacturer recommendation is d i d f 0% t i(tension=14.5%) undersized for 0% tension.
2 ½”, 60oF, L=230 ft 3.94” (+3/4”) 3.25” (tension=21.2%)
Manufacturer recommendation is undersized for 0% tension.
2 ½”, 60oF, L=250 ft FAILS (overcompressed)
3.25” Manufacturer Specs indicate Max Compression Limit to avoid in Spec Notes.
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Overall Conclusion:
When contributing span lengths increase and/or temperatures increase, there is a a d/o te pe atu es c ease, t e e s aneed for wider seals to ensure 0% tension.
The NYSDOT calculator puts these design capabilities into the hands of our Bridge Repair Crews On the Go TechnologyRepair Crews. - On the Go Technology
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