1. Designed with the Paving Professional in Mind
Achieving Quality Joint Construction
Nova Scotia Asphalt User Producer Association
6th Annual Meeting
Larry Spring
LB Performance Paving
Division of
VT Leeboy
Designed with the Paving Professional in Mind

2. THE HEAD OF MATERIAL IS THE MASS OF PAVING MATERIAL THAT LIES DIRECTLY IN FRONT OF AND SPANS THE ENTIRE WIDTH OF THE SCREED.
NINETY-FIVE TO NINETY-EIGHT PERCENT OF ALL MAT FLAWS ORIGINATE FROM PAVING WITH AN IMPROPER HEAD OF MATERIAL.
Slide 2

3. Correct Head of Material Required Depth Required Density
Increased Depth Decreased Density
Head of Material Too High
Decreased Depth Increased Density
Head of Material Too Low

4. Segregation

5. Use of Auger Tunnels to Control Material Flow to the Outer Edges of the Screed
MATERIAL FLOWING FORWARD
MATERIAL CONTROLED BY TUNNEL

6. Auger/Conveyor Overview
Hopper at Least 1/3 Full
Augers Built to Suit Width of Screed - Material Level with Auger Shaft
Conveyors Kept Filled
Slide 6

7. Indication of end of load.
Lack of Material at Augers
Slide 7

8. Joint Construction
TRANSVERSE
JOINT CONSTRUCTION

9. Possible Fretting Here
Transverse or Overnight Joints
Alternative Construction
Possible Fretting Here
Direction of Travel
End of 1st Mat
Start of New Mat
Wedge Transverse Joint
Wood
Ramp (Hand Shaped)

10. Constructing a Transverse Joint
Clear & Square
Constructing a Transverse Joint
Add Joint Paper
Form the Wedge
Roll the Joint

11. Preparation of end of pass joint4 3 2 1
Preparation of end of pass joint

12. Clean & Tack Coat Vertical Edge
Resuming Paving at a Transverse Joint
Wedge Removed
Compacted Mat
Clean & Tack Coat Vertical Edge
Ref: Joints pg. 6

13. Setting the Screed for work
Support the screed throughout it’s width using wood starting blocks or lathes. Center tow point cylinders.
Screeds should be set up correctly before moving off and starting to lay material.
Explain ‘Nulling’ the screed and setting the A of A
A nulled screed simply means that there is some rotary movement in the
depth crank when the screed is relaxed on the reference.
Null the screed by turning the depth cranks CW until the screed rests on the blocks and the cranks become loose. Turn cranks CCW approximately two turns to raise the front of the screed and set the angle of attack ready for laying.

14. Starting Blocks
Blocks are placed at each side of screed to assure equal depth across screed

15. End Gate Adjustments
Keep end gate flush & level When matching a joint
Adjust Spring Loaded end gates down to sub base to get a crisp edge

16. Clean and Trim Joint as Paver Moves Off
Pull off Large Stones
Form Joint with Fine Material
Do not Broadcast Large Stones on to Mat

17. Avoid Broadcasting Larger Stones Across Mat
Bumping Back the Joint
Bumped Material Increases Material Quantity Here Which May Increase Density When Rolled
1st Mat
2nd Mat
Avoid Broadcasting Larger Stones Across Mat

18. Double Check for Parallel Mat and Compaction Factor
Checking the Mat
No Dip Here
Check for Parallel
Straight Edge
1st Mat (Cold)
New Mat (Hot)
Direction of Travel
Double Check for Parallel Mat and Compaction Factor
Ref: Joints pg. 6

19. MAKING GOOD TRANSVERSE JOINTS
1. Maintain full depth & slope at shutdown
2. Good wedge formation
3. Good wedge removal & joint preparation
4. Align paver & screed with previously laid mat
5. Heat screed properly
6. Use lathes under screed to allow for roll-down
7. Null out the screed
8. Fill auger box with correct head of material & set sensors
9. Begin paving at normal paving speed
10. Check & if necessary correct grade & slope
Always:

20. Joint Construction
LONGITUDINAL JOINTS

21. Most surfaces are laid between 12-14 ft wide
Today, most roads must be kept open to traffic
Roads are better laid in one pass (Paving in echelon)
Wide screeds can be 40 to 50 ft wide

22. Joint Deterioration
To This
How do we get…...
From This
Slide 22

23. Types of Longitudinal Joints
Notched Wedge Joint
Wedge Joint
Cut Back Joint
Standard or Tapered Joint

24. Use of Disc Cutter to Form a Clean Edge
Cut Back Joint
Use of Disc Cutter to Form a Clean Edge

25. Cut Away Edge to be Discarded
The Cut Back Joint
1st Mat
Cutting Disc Attached to Edge Compactor on Roller
Cut Away Edge to be Discarded
1st Mat
1st Mat
2nd Mat
Ref: Joints pg. 8

27. Notched Wedge Joint

28. Contractor Designed Notched Tapered Joint Maker

30. Notched Wedge Joint Maker and Roller

31. Always Check Joint Roll Down Behind Rollers for Guidance
Correct Overlap
1/ /2 inches ( mm)
Minimum Required Overlap for Compaction is 1/2 inch 13mm
Always Check Joint Roll Down Behind Rollers for Guidance

32. Causes Bridging Here with Less Compaction
Screed Supported by 1st Mat
Screed
1st Mat
2nd Mat
Limited Density Achieved
Excessive Overlap Onto 1st Mat

33. Avoid Broadcasting Larger Stones Across Mat
Bumping Back the Joint
Bumped Material Increases Material Quantity Here Which May Increase Density When Rolled
1st Mat
2nd Mat
Avoid Broadcasting Larger Stones Across Mat

35. Controlled Steering is a Must
Longitudinal Joints
Need a Good Edge to Follow

36. “Hot” Joint Construction
Keep roller off edge of
previous pass 6” to 8”
Set end gate flush with screed
extension & completely flat
spray end gate frequently
Overlap previous pass ¾” to1” Max
Adjust up or down with manual
or electric screw
Use Automatic Joint Matcher

37. Always: 1. Steer a straight line 2. Adjust screed for proper overlap
MAKING GOOD LONGITUDINAL JOINTS
Always:
1. Steer a straight line
2. Adjust screed for proper overlap
3. Lay correct depth to allow for compaction
4. Strive to minimize segregation at joint edge
5. Prepare the joint well for rolling
6. Do not broadcast loose stones onto fresh surface mat
7. Use best rolling procedures

38. Use a lift thickness that is at least 4 times the NMAS for coarse gradations and 3 times the NMAS for fine gradations.
Consider use of the notch wedge joint (versus butt) for lift thicknesses equal to or between 1 and 3 inches.
Consider the use of infrared joint heaters, especially in cold weather paving.
Use the smallest NMAS mix that is appropriate for the application. This will aid in obtaining the necessary density and also a more impermeable surface.
Smaller size mixes are less permeable at a given in-place air void level.

39. Infrared Asphalt Joint Heater Paver Mounted

40. Infrared Joint Heater trailer Mounted

41. Joint Compaction

42. Compaction Goals Maintain the Grade, Slope & Profile left by the Paver
Apply the fewest passes of the rollers necessary to get compaction
Apply the lowest amount of compactive effort to get the job done
Understanding the Compaction Curve
Slide 42

43. Edge Rolling Unconfined Edge Confined Edge Min 6” Roller Drum

44. Alternative Unconfined Edge
Edge Rolling
Min 6”
Alternative Unconfined Edge
Roller Drum
First Pass Rolling Technique to obtain
density at Unconfined Edge

45. Rolling a Longitudinal Joint... First Alternative

46. Rolling the Longitudinal Joint
Roller Drum
Overlap
Joint 6 inches
“Vibration On”
Cold Side
1st Lane
Hot Side
2nd Lane

47. Rolling a Longitudinal Joint… Second Alternative

48. Rolling a Longitudinal Joint
Roller Drum
Vibration On
4 - 6 inches
COLD
HOT
Note: Requires two vibratory passes.

49. Overlap 2nd Pass
Roller Drum
6 ” Min.
Overlap
2nd Pass
1st Pass

50. Rolling a Crown Overlap drum 3 - 6 inches over the crown. Roller Drum
Note: Roll from the low to high side of the crown
Never roll directly on top of the crown

51. It’s All Up to You! Quality Paving Joints Must be Your
Goal!
Slide 51