research paper perpetuation of airport pavements233 int. j. struct. & civil engg. res. 2013...

233

Int. J. Struct. & Civil Engg. Res. 2013 Jalal Uddin and K Jagdeeshwar, 2013

PERPETUATION OF AIRPORT PAVEMENTS

Jalal Uddin1* and K Jagdeeshwar1

1 Assistant Professor-Civil Engineering, Jaya Prakash Narayan College of Engineering, Mahabubnagar 509 001, Andhra Pradesh.

*Corresponding author: Jalal Uddin,[email protected]

ISSN 2319 – 6009 www.ijscer.comVol. 2, No. 4, November 2013

© 2013 IJSCER. All Rights Reserved

Int. J. Struct. & Civil Engg. Res. 2013

Research Paper

The need to Perpetuation our airfield pavement infrastructure is paramount to insuring the viabilityof transportation of people and goods. Preventive maintenance plays an important role in thePerpetuation of airfield pavement infrastructure. A successful preventive maintenance programcannot function without the support of many features associated with pavement managementsystems (e.g., pavement inventory, condition assessment, and the framework for the identificationand prioritization of pavement preservation treatments). The purpose of a preventive maintenancetreatment is to prevent premature deterioration of the pavement, retard the progression ofpavement defects, and cost-effectively extend the life of the pavement. The objective is to slowdown the rate of pavement deterioration and effectively increase the useful life of the pavement.A preventive maintenance treatment is not determined by the type of treatment, but by the reasonwhy the treatment is performedThe effectiveness of preventive maintenance is largely dependenton the timing of maintenance activities. The development and implementation of a preventivemaintenance program should be done in a collaborative manner, and should be supported bytraining and educational activities. Perpetuation in essence, is caring about the future conditionof the world we live in. The decisions we make today have consequences on our environmenttomorrow. They are either positive or minimal in nature, or they are large and far reaching andvery negative, and we have to live with it. The legacy we leave for our children and grand childrenwill determine if we were good stewards of what we had been given. Perpetuation is the “long-term” philosophy that shows we recognize these important environmental issues.

Keywords: Perpetuation, Estimation, Environmental issues

INTRODUCTIONPavement PreservationPavement perpetuation represents a proactiveapproach in maintaining our existing highways.It enables State Transportation Agencies

(STAs) to reduce costly, time-consumingrehabilitation and reconstruction projects andthe associated traffic disruptions. With timelypreservation, we can provide the travelingpublic with improved safety and mobility,

234


reduced congestion, and smoother, longerlasting pavements. This is the true goal ofpavement preservation, a goal in which theFHWA, through its partnership with the States,local agencies, industry organizations, andother interested stakeholders, is committed toachieve.

Categories of PavementPreservationWhy the Interest in Pavement Preservation?

• Airport Pavements - a Huge Investment

• Important to Preserve Investment

• Effective Pavement Preservation Program:

– Right Pavement

– Right Treatment

– Right Time

Figure 1: Pavement Preservation

Pavement Condition vs. TimeThis curve demonstrates the importance ofselecting the “right time” for pavementtreatments. We want to be programming mostof our work at this stage (point to $1 spot), toavoid having to do the more expensive workhere ($4 spot)

Figure 2: Categories of PavementPreservation

Figure 3: Pavement Condition vs. Time

Traditional ApproachThe traditional approach allows pavements todeteriorate until the condition reaches such apoint that major rehabilitation is req’d.

Some agencies have based theiroperations on the premise that “if it aint broke;don’t fix it”. They may say we can only afford tofix the very worst pvmts. In the end thisapproach costs MORE MONEY

• Allows deterioration to fair to poorconditions.

• Major rehabilitation or reconstructionrequired.

235


• Clearly reactive, time consuming andcostly.

Once structural damage has occurred thenpreventive maintenance treatments are of littlevalue.

Applying PM treatments to unsuitablepavements has been its biggest barrier togaining widespread acceptance for the PMconcept.

• Applies low-cost preventive treatments.

• 5 to 7 year life.

• Timing is critical Good Condition, Nostructural damage.

Main Components of AirportPavement Management

Figure 4: Rehabilitation or Reconstruction

Proactive ApproachA true preservation approach involves theapplication of a series of successful low cost,preventive maintenance treatments thatindividually will last for several years.

The key is to apply the right treatment at theright time. This means applying it to thecandidate pavement when it is still in goodcondition and there is no structural damage.

Figure 5: Main Components of AirportPavement Management

236


Step 1: Design of APMSWhen 1st implementing a PMS, or whenconsidering how to improve the one you have,there are some “management” aspects toconsider.

• Who will operate the PMS- will it be doneby in-house staff or by a consultant?

– It is important to secure an adequatebudget to implement and continueoperation of the PMS (benefits willincrease over time, so this shouldn’t beviewed as a one-time project whensetting a budget.)

– To be successful, the PMS should beintegrated (not separate from) yourdecision making process and supportedby upper management.

– Management Considerations:

Decide who will operate

Budget for operation

Integration into decision making

Support by upper managementdepartures of each A/C type) for eachsection.

– Pavement structure

– M&R history

– Pavement condition

– Traffic data

Step - 2: Pavement Condition Data• Inventory = basic building block of APMS

• Sectioning of network

– Homogeneous units

– Similar pavement structure and condition

– Basic unit for decision making (repairunit)

Sectioning at Small Airport

Figure 6: Sectioning at Small Airport

Sectioning at Large CommercialAirport

Figure 7: Sectioning at Large CommercialAirport

• Inventory information for each section:

• For each section, it is useful to input info onthe pavement composition (structure) andits maintenance history. Sometimes this isnot readily available at the outset, but canbe populated over time. Pavementcondition is an essential element of thePMS that we’ll discuss in a moment. Forany airport that has some variation in trafficthroughout the facility, it is important include

237


traffic data (i.e., annual departures of eachA/C type) for each section.– Pavement structure– M&R history– Pavement condition– Traffic data

Pavement Condition Data• As a minimum, Condition Data consists of

type, severity and quantity of distress. ASTMmethod identifies 16 distress types for ACand 15 distress types for PCC. Some A/P’s also collect roughness, friction andstructural data.

• Optional Discussion- only about half dozenthat are predominant at most airports, thataffect pvmt preservation needs (for AC-L&T; rut; weathering; block; jet blast; oil-spill); for PCC-Jt seal; Jt spall; Fault; cornerbreak; L- cracks. FOD applies to both AC& PCC and is an important considerationin M&R selection.– Surface Distress (PCI Method)– Roughness– Friction

Pavement Condition Index PCIMethodThe distress data is then used to calculate anoverall Pavement Condition Index (PCI), whichis a scale from 0-100 as shown.

Figure 8: Pavement Condition

Figure 9: Pavement Condition Index

Survey-Pavement CharacteristicsEvaluated

Runways Taxiways and Other Facilities

PavementCharacteristic

Pci 78 3.4 54 3.3

Roughness 12 N/A 4 N/A

Friction 22 N/A 8 N/A

Fwd Testing 18 3.7 12 N/A

Usa

ge %

Ave

rage

Freq

uenc

y(Y

ears

)

Usa

ge %

Ave

rage

Freq

uenc

y(Y

ears

)

What does our survey say, About pvmtcharacteristics typically evaluated: 78% do aPCI survey on R/W’s; a small % collect info onroughness, friction and structural strength (asdetermined by FWD testing). You can seethere are different #’s for T/W’s and otherfacillities. Take note that the avg. frequency ofsurveys is about 3 years. I’ll comment on that

238


later.

Evaluation for PreventiveMaintenanceEvalns can be made specifically for PM – i.e.,determine when it should be applied. Ideallyshould be at time when most effective (typebefore distress progresses and moreexpensive treatment needed. The ideal timeto take care of the single crack shown onleft(e.g., route and seal) is Now; not 1-2 yearsfrom now when multiple cracks have formedand begun to ravel. The crack on Left couldprogress to condition on Right is just a coupleof years.

• Consequently, cond surveys should bedone annually to catch pvmts at right time

• Survey says– avg. 3 year cycle (range 1-10years). This is an area for improvement

– PM should be applied when most cost-effective

– Condition surveys ideally done annually

– Survey- avg frequency of PCI survey = 3years

Performance PredictionSince planning and budgeting for 5 or moreyears, it’s necessary to estimate future pvmtpreservation needs, so we need to predictfuture conditions.

• Figure shows pavements A and B withsame current PCI, but B predicted todeteriorate faster than A, so it needstreatment sooner

• How do we know B will deteriorate fasterthan A?- there are several methodsavailable to predict future conditions—many are based on “family modeling”,

– Typical planning period = 5 years

Figure 10: Ideal Time for Crack Filling

Past ideal time

Figure 11: Performance Prediction

Now +5

Predicted performance

0

100

Minimum acceptableservice level

Now Now + 2

Pavement age, years

Past performance

Remaining ServiceLife

A B

Pav

emen

t C

ondit

ion I

nde

x (

PC

I)

Now +5

Predicted performance

0

100

Minimum acceptableservice level

Now Now + 2

Pavement age, years

Past performance

Remaining ServiceLife

AA BB

Pav

emen

t C

ondit

ion I

nde

x (

PC

I)

– Need to predict future conditions

– Several methods (many based on “familymodeling”)

Step 3 - Technology of PavementTreatments• Selecting appropriate treatments is

important part of pavement management

239


• Synthesis contains Catalog:

– 24 AC treatments

– 24 PCC treatments

Step 4 - Identification of Needs• Based on condition surveys, performance

predictions, and criteria built into APMS

• Criteria based on 3 concepts:

– Maintenance policies

– Level of service

– Trigger values

• MicroPaver identifies 2 levels of needs:

– Localized maintenance and repair

Year 1-specific treatments based ondistresses

Future years- $ based on PCI ranges

– Generalized major M&R

Unit $ based on PCI level

Level of Service TargetsThis graphic shows the use of all of thepotential DECISION CRITERIA mentionedearlier.

• A specific PCI level can be programmedinto the APMS so that a treatment such ascrack filling (high PCI level) or Overlay (lowerPCI) are “triggered”.

• A target level (PCI) can be established forthe overall network and M&R programmedover a period of years to achieve this goal.

• Similarly, a Min acceptable LOS forindividual sections can be input so thattreatments are programmed when the pvmtfalls below this level.

• Often the person developing a CIP may runreports using several of these criteria, thendevelop a final CIP based on some comboof these. Minimum safety-related levels ofservice are typically defined in terms ofindividual pavement defects, such aspotholes, cracking, and wheel track rutting.

The minimum acceptable level of serviceis the minimum condition for individualpavement sections. The sections at or belowthis level should be improved at the firstopportunity.

Trigger values are usually associated withspecific pavement preservation treatments(such as sealing cracks in asphalt concrete

Figure 12: Pavement Treatments Figure 13: Level of Service Targets

Pavement Age

Pav

emen

t C

ond

itio

n

Minimum safety-related level of service for individual sectionsin terms of individual defects

Minimum acceptable level of service for individual sections

Trigger value for crack sealing

Target level of service for average network condition

Trigger value for an overlay (mill and fill)

Pavement Age

Pav

emen

t C

ond

itio

n

Minimum safety-related level of service for individual sectionsin terms of individual defects

Minimum acceptable level of service for individual sections

Trigger value for crack sealing

Target level of service for average network condition

Trigger value for an overlay (mill and fill)

240


pavement or sealing joints in concretepavement) and are related to the need to applya preservation treatment at the right time tobe effective, or before the pavement reachesa condition where a different, more expensivetreatment would be required.

Target levels of service represent adesirable level of service for the entirepavement network or a portion of the network.

Step 5 - Prioritization, Planning andBudgeting• Short Term

– Simplified analysis- no future M&Ralternatives

– Establish priorities based on:

Safety

Cost-effectiveness

Critical condition level

• So, we talked about Short and Long- termplanning, Now, back to short vs long-termprioritization:

• SHORT TERM-alternative future alts notconsidered

• Priorities can be set based on SAFETY(e.g., if distresses with FOD potential-highpriority to fix); COST EFFECTIVENESS-typ favors projects that can be done beforesignificant damage occurs – in other words-preventive maintenance; CRITICAL LEVELOF SERVICE or condition level - unlike PM,this essentially means a “worst first”prioritization which is usually the reverse ofthe $-effectiveness approach, but airportsare still reqd to provide for safe aircraftoperations and to provide a min. level of

service, therefore, short-term planningbudgets typically combination of each.Separate priority lists can be created thenselections made from each, applying somejudgment.

• Long-Term:

– Multi-year prioritization of alternativetreatments

– Typically based on cost effectiveness

• Long term-programmed treatments in the“out years”, are not based on immediatesafety problems and alternatives areselected based on their $-effectiveness(explained further on next slide)

Budget Development ProcessStep 5 - Budget Evaluation• Budget Evaluation Tools:

– Monitoring performance trends

– Monitoring expenditures over time

– Tracking backlog of un-fundedpreservation needs

– Evaluating consequences of budgetlevels on future conditions

Step 6 - Project Design andImplementation• Design:

Figure 14: Budget Development Process

241


– Network level APMS- provides multi-year M&R program

– Project level APMS- provides finaltreatment and technical details

• Implementation and Monitoring:

– APMS useful to monitor M&Rperformance

• Survey

– Only 45% using APMS to monitorperformance of past M&R

Step 7 - Operation, Sustainabilityand Enhancement• Success of pavement preservation

program and its sustainability closely linked

• Document and communicate successes totop management

• Seek sustained preservation funding

Preservation TechniquesSeveral maintenance/rehabilitation methodsare available to the agencies responsible formanaging and protecting the pavements. Theyinclude:

Preventive maintenance—used to preservethe pavement in good condition and caninclude the following treatments:

Crack sealants,

Fog seals,

Chip seals,

Slurry seals and microsurfacings, and

Thin hot-mix overlays.

To achieve best results for all treatments,proper techniques and mixing methods mustbe followed.

CONCLUSION• Preservation in essence, is caring about the

future condition of the world we live in. Thedecisions we make today haveconsequences on our environmenttomorrow. They are either positive orminimal in nature, or they are large and farreaching and very negative, and we haveto live with it. The legacy we leave for ourchildren and grand children will determineif we were good stewards of what we hadbeen given. Preservation is the “long-term”philosophy that shows we recognize theseimportant environmental issues

• When pavements deteriorate to fair or poorcondition they require rehabilitation torepair structural damage and restorepavement conditions—a costly, time-consuming activity. Hi-Lite will help plantreatments for minimal disruption of normalactivities.

• Reduces pollution and the demand for finiteresources.

• Increases the sustainability of a significantnational asset.

• Is environmentally responsible.

• Is ultimately cost-effective.

BIBLIOGRAPHY1. Brian Edwards (2005), “The Modern

Airport Terminal: New Approaches toAirport Architectur”.

2. Norman J Ashford, Saleh Mumayiz andPaul H Wright (2011), “AirportEngineering: Planning, Design, andDevelopment of 21st Century Airports”.

242


3. Paul H Wright, Airport Engineering.

4. Robert Horonjeff, Francis McKelvey,William Sproule and Seth Young (2010),

Planning and Design of Airports, 5th

Edition, McGraw-Hill.

research paper perpetuation of airport pavements233 int. j. struct. & civil engg. res. 2013...

Documents