concrete paving association workshop march 12, … paving association workshop march 12, ... (4 per...
TRANSCRIPT
Gordy Bruhn, Concrete Rehab Specialist, MnDOT Concrete Unit
Matt Zeller, Concrete Paving Association of Minnesota
MnROAD and Research
Construction Materials
CPR, Inc.
Diamond Surfaces, Inc.
Interstate Improvement
PCI Roads
Simplex Construction Supplies
MnDOT District 3
Full Scale Investigation of other CPR projects constructed between 2007 and 2012
Was the switch from 11 dowels to 6 (3 per WP) or 8 (4 per WP) depending on traffic going too far? But it works for retrofit dowel projects…
Where did the material go? We used more than we needed? Did it break down, was it durable?
Is Spec constructible?
◦ Place the bonding agent into the drilled holes to completely fill the void.
Road MP 2010 ADT 2010 %Trucks
Dowels per lane
CPR Year
I-90 138-145 7,668 25.4 6 2009
I-90 185-193 11,416 11 11 2010
I-94 157-194 43,500 10.3 6 2009
I-94 209-217 100,725 9.5 8 2010
MN23 112-124 3,290 12.9 8 2011
MN77 1-5 65,000 2.2 11 2007
During investigations we found a lack of epoxy adhesive / grout around the dowels from all of the Contractors
“I watched them install dowels on many projects and thought they were good.”
Change standard back from 8 dowel bars to 11 dowel bars due to problems we have encountered with workmanship
Time to discuss with Concrete Industry and educate Inspection Personnel
December of 2012 Focused on premature failure of full depth
repair project Investigation of other projects and
information sharing with Industry “It has been working for 30 years – what’s
changed?” Workmanship and Best Practices were the
end result◦ How good can we really do? Let’s go to
MnROAD and find out….
PCi ROADS retrieved some full depth repair removals from the I-94 CPR project
Drilled holes into both sides of panels for dowel bar installation and delivered to MnROAD Pole Barn
Let slabs warm up for
a week
All concrete rehab
contractors and major
material suppliers were present to install
What did we try?◦ Epoxy dip and stick
◦ Epoxy double dip
◦ Epoxy – fill and twist
◦ Grout box method
◦ Grout dip and stick
◦ 1 hour old grout
◦ Grout capsules
◦ Polygrip epoxy
Also tried additional brushing and compressed air and grout rings to see if any made a significant impact on the performance of the repair
Had problems with epoxy due to cold temperatures
PCi Roads came and cut 4” off of each side to view the voids around the dowel bar to check effectiveness of installation
University of Minnesota used MIRA to investigate filling of voids non-destructively
MnDOT randomly cored every CPR project in 2013
One Contractor took initiative to core and check their own workmanship
Most effective cause for Contractor to change was when MnDOT cored each project – even when Contractors were working on multiple projects
1” and 1.25” diameter dowel bars
All lanes diamond ground
No grout, modified grout bag, grout capsule, epoxy (2 types)
Controlled location
FWD testing seasonally
Coring
Monitoring over time
MnROAD Mainline - Old Westbound Interstate I-94 (By-Pass)
13 cells 9” JRCP / 6” Class-6 Base / Clay (1973)
each cell has 3 joints = 81 feet long = both lanes Estimated 140,000 Rigid ESAL/Year
28,500 ADT - 13% Trucks
Starts MP-199 1
East
joint# 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1
feet 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5
1 2
joint# 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 2
feet 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5
2
West Note: Updated - July 24, 2013
Need to discuss the -
joint# 1 2 3 1 2 3 1 2 3 Monitoring (FWD Joints, Distress, LISA Ride)
feet 13.5 27 27 13.5 13.5 27 27 13.5 13.5 27 27 13.5 Analysis - Need to discuss
FWD Point pre-full depth repair
26 points (2 per cell)
marked on roadway
Diamond Grinding Diamond Grinding Diamond Grinding
1" Dowels 1.25" Dowels
Full Depth Joint Repair Full Depth Joint Repair No Repair
Epoxy - Rezi Weld Epoxy - Rezi Weld "control"
Cell 980 Cell 981 Cell 982
Epoxy - Powers Epoxy - Powers
1.25" Dowels 1" Dowels 1.25" Dowels 1" Dowels 1.25" Dowels
Grout - Dip Method Grout - Capsule Method Grout - Capsule Method
Diamond Grinding Diamond Grinding Diamond Grinding Diamond Grinding Diamond Grinding
Full Depth Joint Repair Full Depth Joint Repair Full Depth Joint Repair Full Depth Joint Repair Full Depth Joint Repair
1.25" Dowels 1" Dowels 1.25" Dowels 1" Dowels
Cell 975 Cell 976 Cell 977 Cell 978 Cell 979
1" Dowels
Full Depth Joint Repair Full Depth Joint Repair
No Grout No Grout Grout - Bag Injected Grout - Bag Injected Grout - Dip Method
Full Depth Joint Repair Full Depth Joint Repair Full Depth Joint Repair
Cell 973 Cell 974
Diamond Grinding Diamond Grinding Diamond Grinding Diamond Grinding Diamond Grinding
Cell 970 Cell 971 Cell 972
Pavement Section: Interstate I-94 (By-Pass)◦ 9” JRCP/6” Class-6 Base / Clay (1973)
◦ Estimated 140,000 Rigid ESAL/Year
◦ 28,500 ADT – 13% Trucks
Since Test Section Installations (8/15-16/13)◦ Traffic on By-Pass ~ 88 Days
◦ Estimated 500,000 Rigid ESALs
◦ ~14,000 ADT – 14% Trucks in Driving Lane
Cells 970 - 981 (w/patches)
East Patch "X" West
Passing
Driving
X, approach, patch
X, leave, pavement
X, approach, pavement
X, leave, patch
Cell 982 (control w/o patch)
East Joint "X" West
Passing
Driving
X, leave, pavement
X, approach, pavement
Larson and Smith (2005) suggest that “doweled joints with LTE of 85 percent or less and/or a differential deflection greater than 5 mils in five years or less are unlikely to provide satisfactory long-term performance.”
Values reflect new construction – I believe adaptive to performance of full depth repairs
Source: Guide to Dowel Load Transfer Systems for Jointed Concrete Roadway Pavements (Sept 2011)
Typical “Action” thresholds range from 50 to 70 percent Load Transfer Efficiency (LTE) considering LTE only
Source: Guide to Dowel Load Transfer Systems for Jointed Concrete Roadway Pavements (Sept 2011)
Larson and Smith (2005) suggest that “The maximum differential deflection criteria of 5 mils may help evaluate dowel looseness or the possibility of delaminations in the concrete at the dowel bar level.”
Source: Guide to Dowel Load Transfer Systems for Jointed Concrete Roadway Pavements (Sept 2011)
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25 C
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25 C
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Dowel bar looseness
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25 C
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Dowel bar looseness
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Dowel bar looseness
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Cells 970 - 981 (w/patches)
D1D10 D3
approach, pavement
%100D1D3LTE
D1D10 D3
leave, patch
%100D1
D10LTE
D1D10 D3
approach, patch
%100D1D3LTE
D1D10 D3
leave, pavement
%100D1
D10LTE
direction of traffic and testing
Dowel bar looseness
NG1 NG1.25 GB1 GB1.25 GD1 GD1.25 GC1 GC1.25 EP1 EP1.25 ER1 ER1.25 C
The FHWA still evaluates MnDOT on the smoothness of the roadways. Perhaps even more stringent than before
MnDOT is repairing older roads either a first or second time
Seasoned veterans are retiring
Night and weekend construction puts additional strain on the workers
Increased truck traffic over time
Research to date shows that if the hole is properly filled prior to installing the dowel bar, it seems to provide a sufficient load transfer efficiency
Lack of material around the dowel bar indicates a high probability of premature failure (possibly < 5 yrs)
Rapid construction requirements have pushed MnDOT to be more prescriptive rather than just specifying following manufacturer’s recommendations
We will continue to monitor the test sections at MnROAD for the next few years including adding ride periodic ride measurements
In my opinion …
◦ “Full Depth Repairs are an excellent technique for concrete pavement preservation – just remember it is sometimes the simple things that can cause the biggest problems.”
◦ “Proper project selection and Contractor Workmanship are the keys to success!”