1. Longitudinal Joint Density Test Results
December 12, 2012
Garth D. Bridenbaugh, P.E.
Pennsylvania Department of Transportation
BOPD, Innovation & Support Services
Quality Assurance Section

2. Longitudinal Joint Data Summary
How Far Have We Come?
Longitudinal Joint Data Summary
Year
Density Lots
Avg. Joint Density
Avg. Roadway Density
2007 18
87.8%
93.9%
2008 43
88.9%
94.1%
2009 29
89.2%
2010
No data, transition to PWL spec.
2011
137
91.1%
2012
158
91.5%
94.0%

3. Impact on Lot Payment Summary
-$12,000
+$5,000
Disincentive
No Pay Adjustment
Incentive 50 80
100
PWT

4. 2012 Statewide Pay Impacts 158 density lots on 51 projects (773 cores)
75% bonus lots
18% no pay adjustment
7% penalty lots
$468,300 total bonus
$62,976 total penalty

5. Corrective Action
Lots with avg. density < 88% Gmm require corrective action
Contractor must seal the joint with PG at no cost to Department
4 lots of 158 required corrective action in 2012

6. US 322

7. US 422

8. Interstate 79

9. Warm Mix vs Hot Mix

10. Notched Wedge vs Vertical

11. By Highway Classification

12. Crowned vs Uncrowned Roadways

13. Mix Size and Type

14. 2011-12 Bonus/Penalty by Individual Contractor
Total bonus = $729,925
Total penalty = $162,192

15. More 2011-12 Joint Density Info.
686 linear miles of joint tested
1450 joint core samples
93 total projects statewide
30 different paving contractors
Notched Wedge Joint
Core Hole

16. Where is PennDOT Heading?
Raising the lower specification limit from 89% to 90% for joint density
Lots ≥92.0% avg. density, full bonus
Lots ≥89.0% but <90.0% avg. density, penalty cap of $1,000 per sublot

17. 2012 Test Results 2012 results under proposed changes:
52% bonus (was 75%)
30% no adjust. (18%)
18% penalty (7%)
Bonuses still more than
double penalty $

18. Why Joint Density?
Lower permeability reduces chance for moisture damage
Higher density reduces the permeability of the pavement in place.

19. Keeping water out of our joints
Most research suggests that…
densities should be about 92% to minimize permeability
Joint densities below 90% begin to see an exponential increase in permeability as density decreases

20. Various Studies on Permeability
Chart excerpted from NCHRP Project 9-27
September 2004

21. Joint Density Spec. Impacts
Overall 3.7% increase in joint density (87.8% to 91.5%) since outset in 2007
Improved joint density is expected to lead to better long term performance
Doesn’t solve all problems
Anticipated lower maintenance costs
Congratulations on a job well done, let’s take the final step forward!