what is a resource? any physical or virtual entity of limited availability a new or reserve supply...
TRANSCRIPT
What is a Resource?
• Any physical or virtual entity of limited availability• A new or reserve supply that can be drawn upon
when needed • Something that one uses to achieve an objective• An input to be used in an activity, especially
production• The ability to deal resourcefully with unusual
problems; "a man of resource"
Streets and Local Roads Resources
Philip KresgeSr. Director, National Resources
National Ready Mixed Concrete Association
Streets and Roads Thickness Design
Longitudinal joint
Transverse joint
Subgrade
Subbase
Surface Texture
Surface smoothnessor rideability
Thickness Design
Dowel bars (may be optional)
Concrete materials
Tiebars
Understanding Design Optimization
• Design optimization is the balance of performance features and costs.
• Design optimization involves adjusting variables to:
• Achieve long life (durability)
• Reduce initial costs
• Minimize maintenance and rehabilitation costs, and/or
• Enhance sustainability.
Introducing StreetPave
• Software tool primarily for streets and roads• Uses mechanistic-empirical modeling for
thickness determination (like MEPDG but less complex)
• Direct comparisons of concrete and asphalt designs
• Allows life cycle cost analysis (LCCA) to compare “hard costs” (if local cost & performance data available).
• Approved by VDOT for streets and roads design
Global Inputs in StreetPave
• Project information• Design life• Reliability*• Failure criteria*
• Terminal serviceability• Percent cracked slabs
*Should be selected based on policy and experience
StreetPave Input Examples
First screen of walk-through wizard
Co
st
Initial CostRehabilitation Costs
Maintenance Costs
Salvage Value
Time
Co
st
Net Present Worth
Time
Life-Cycle Cost Analysis
Combines all present and future costs (benefits)
Where to find StreetPave
• Available in two formats• Full-feature Windows®
version in available from ACPA website at www.acpa.org/bookstore
• Free, limited feature web-based version on ACPA’s website at www.acpa.org/StreetPave/index.asp
What can be done with an existing asphalt pavement?
Concrete Overlays
Historical Review• Began in late forties and early fifties• First used on Airports and Secondary Roads• In mid-seventies acceptance grew• By late eighties this was normal practice• Significant amounts of state and federal
highways have been rehabilitated this way
Concrete Overlays
Why Concrete Overlays?
• To enhance curb appeal• To rehabilitate existing surface • To add structural capacity• To save money (reduce maintenance)• To enhance safety
• Lighting• Skid resistance
www.cptechcenter.org/publications/overlays/index.htm
Ultra-Thin Whitetopping
• By Definition• Thicknesses between 2” and 4”• Bonded to underlying surface• Short joint spacing 2’ – 6’ panels• Existing asphalt pavement as base
Rte. 30, Lancaster, PA
• Intersection of Rte. 30 & Oakview Rd. • In front of PennDOT County
Maintenance Facility• Placed Oct. 1995• Existing asphalt pavement less than
three years old• In excess of 1,500 trucks per day• Severe rutting/shoving
Copyright ©2010 – NRMCAWWW.NRMCA.ORG
Existing asphalt pavement was only 2-3 years old. Severe rutting, in excess of 5 inches, was a continual problem.
Smaller vehicles actually “bottomed out” on ridge of asphalt!
Copyright ©2010 – NRMCAWWW.NRMCA.ORG
High/Early Strength concrete mix used to facilitate opening to traffic in 24 hrs.
Copyright ©2010 – NRMCAWWW.NRMCA.ORG
Rte. 30, Lancaster, PA
• Placed Oct. 1995• Over 1,500 trucks
per day • 8.2+ million trucks
in 15 yrs. service
Copyright ©2010 – NRMCAWWW.NRMCA.ORG
• Available through the National Concrete Pavement Technology Center
• www.cptechcenter.org
Copyright ©2010 – NRMCA
WWW.NRMCA.ORG
Other Resources
Training presentation available in-house or as online webinar
Contact Bob Long at ACPA for details
Life-Cycle Costs - Executive Overview
Life-Cycle Costs - Technical Fact Sheet
Sustainability Considerations
www.nrmca.org
www.pavement.com
