two-lift paving - contractor's viewpoints
DESCRIPTION
A Two-Lift concrete Paving (2LCP) workshop was organized as a part of the Texas Department of Transportation (TxDOT) project 0-6749: Feasibility Study of Two-Lift Concrete Paving (2LCP). This workshop was conducted at the J. J. Pickle Research Campus (PRC), The University of Texas at Austin, Austin, TX on May 23rd, 2013. Dr. Jiong Hu, Texas State University, Research Supervisor, and Dr. David Fowler, The University of Texas at Austin, Co-Research Supervisor, co-chaired the workshop. The workshop offered the option of attending in person or remotely through webinar. Fifty-one attendees were present remotely or in person; 28 in person and 23 persons remotely.TRANSCRIPT
Two Lift Paving
Contractors Perspective
Two Lift Paving Workshop
Austin, Texas
May 23, 2013
Tim Gerhardt
Koss Construction Company
Overview
• Concept
• Planning
• Scheduling
– Delays– Delays
• Test Section
– Lessons Learned
• I-70 Paving
Concept
• European Scan Tour
– KDOT Representative
• Market Need
– Air Void Problems– Air Void Problems
– Aggregate Quality of local market
– Extended Pavement Life
• Appropriate Project / Location
• Exposed Aggregate Surface
Concept – Market Need
Concept - Project
• I-70 in Saline County, Kansas
– 2 year pavement reconstruction project
• WBL in 2007
• EBL in 2008• EBL in 2008
– Rest Area on each side
• Ideal for test sections
– Revised Typical Section Required 24’ Paving
• Uniform Shoulders on Variable Granular Base
Planning
• Preliminary Discussion
– April 2007 – Manhattan, KS
• KDOT, FHWA, CP Tech Center, KSU, Koss
• Highways for Life
• Workshop • Workshop
– June 2007 – Abilene, KS
• Dr. Hermann Sommer (Austrian Engineer)
• CP Tech Center
• Dr. Rob Rasmussen
Planning
• Mix Designs
– Stiffness of Bottom Lift
– Durability of Top Lift
• Equipment and Logistics
– Delivery and placement of bottom lift – Delivery and placement of bottom lift
• Stiffness
• Haul Road v. Front of Paver
– Delivery and placement of top lift
• Minimize deformation of bottom lift
– Production and Delivery of Two Mixes
Planning
• Test Section
– Expectations
– Location
– Complexity– Complexity
Scheduling
• Test Section
– Late Summer / Fall 2007
• 2007 Season – Extremely Wet
– Paving Crew Unavailable
– Spring 2008
• More economical to re-schedule to location where a paving • More economical to re-schedule to location where a paving crew was already working
– US-69 Side Road
» Minimal risk
» District IV
• 2008 Season – Extremely Wet
– Paving completed in June 2008
Test Section
Test Section
Test Section
Test Section
Test Section
Test Section
I-70
• Plant
– Dual Drum
– Two Silos
• Split• Split
– Aggregate Bins
• Four
I-70
• Delivery
– Product from either drum
– Truck could delivery either
– Color Coded Cards– Color Coded Cards
I-70
• Delivery
I-70
• Placement
– Haul Road
– Spreaders
I-70
• Placement
– Top Lift
• Distance
I-70
I-70
I-70
I-70
I-70
Jointing
Jointing
Jointing
Results
250
300
350
400
Total Length
Top Length
0
50
100
150
200
Millim
ete
rs
Top Length
4 per. Mov. Avg. (Top Length)
Conclusion
• Practical Application
• Limited Production Impact
• Economical
– Economize bottom lift– Economize bottom lift
– Extended Pavement Life
• No Problem
• Team Effort