Types of Joints in Concrete Pavements Why Seal Joints? Types of Sealants Proper Silicone Installation Inspection and Project Review Common Issues and

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Lucas Sutton
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2 Types of Joints in Concrete Pavements Why Seal Joints? Types of Sealants Proper Silicone Installation Inspection and Project Review Common Issues and Troubleshooting Proper Hot Pour Installation Proper Compression Installation Joint Re-sealing Best Practices Crack Sealing Installation Best Practices

3 Minimizes water & incompressibles into pavement system Reduces subgrade softening, pumping and erosion of fines and spalling Prevents Joint Associated Distress? Reduces Noise (Joint Slap) Sealant Nozzle Reservoir Backer Rod

4 FHWA Sealant Effectiveness Study AASHTO New Design Guide

5 A key outcome of this project is advancement of a mechanistic tool for analysis of specific combinations of traffic, climate, base materials, and sealant condition on subbase erosion and pavement performance.

6 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Furnish and Install Cleaning Reservoir Cut Initial Cut * ACPA Relative Cost Study

8 Prevents Incompressible from Lodging in the Joint Slab Growth and Blow Ups

9 Prevents Water from Entering the Subgrade: PCCP -Prevents subgrade erosion -Voids beneath the slab

14 Joint Slap Adds 5 dba to Overall Pavement Noise at 70 MPH

16 Adhesive Failures Cohesive Failures % Damaged or Missing When the Sealant is No Longer Serving its Intended Function

18 Crafco 221 = yrs Crafco 231 = yrs Dow 888 SL = 12.8 yrs Dow 888 = % to 348% Increase for Silicone

20 Old Concrete New Concrete

Sealant Performance Depends On: Design Factors (See ACPA

and Installation Conditions Required Performance Period

installation Silicone & Compression Seal Should be

23 Sealant Performance Depends On: Design Factors (See ACPA App Website) Anticipated Movement Construction Schedule and Installation Conditions Required Performance Period Noise Considerations Sealant Selection---Proper Design and Specification for Application Joint Preparation---Clean, Dry, and Bondable Sealant installation Silicone & Compression Seal Should be Recessed Hot Pour Should be Flush Filled Backer Rods Appropriate for Sealant Type Primer?

24 Hot Pour Sealants: 25% Extension Silicone Sealants: 50% Compression to 100% Extension Compression Seals: 15% min Compression to 50% Extension

25 A= ¼ to 3/8 B= ¼ to 3/8 C= ¼ to ½ C/B > 1 Silicone Silicone Backer Backer Rod Rod PCCP

26 *Joint Width 1/4 3/8 1/2 5/8 3/4 7/ /8 1 1/4 1 3/8 1 1/2 Minimum Sealant Recess 1/4 1/4 5/16 5/16 3/8 3/8 3/8 1/2 1/2 1/2 1/2 Backer Rod Diameter 1 3/8 1/2 5/8 3/4 7/ /4 1 1/2 1 1/2 1 3/4 2 Sealant Bead Thickness 1/4 1/4 1/4 5/16 3/8 7/16 1/2 1/2 1/2 1/2 1/2 Minimum Joint Saw/Reservoir Depth 1 1/8 1 1/4 1 1/2 1 3/4 1 7/ / /8 3 1/8 3 3/8 Minimum Backer Rod Depth 1/2 1/2 5/8 11/16 3/4 13/16 7/ Estimated Usage Non- Sag Estimated Usage Self-leveling(ft./gal)

27 Min Compression = 15% Max Compression = 50% Courtesy DS Brown

31 0.14 Phoenix, AZ 0.12 Bismarck, ND San Diego, CA 0.1 Crack Movement (in) Month of Construction

33 Material Selection Sealant Type Hot Pour Silicone Compression Seals Backer Rod Type (see SNS Group website) Open Cell Closed Cell Hybrid Preparation Sawing Cleaning Installation Inspection

sidewalls/provides maximum sidewall adhesion.

this eliminates three-sided joint adhesion

Closed-cell foam technology/does not allow

34 Sized to be 25% larger than joint width Controls depth of sealant ensuring proper joint design ratio. Forces sealant against joint sidewalls/provides maximum sidewall adhesion. Sealants will not adhere to backing rod and this eliminates three-sided joint adhesion failure. Closed-cell foam technology/does not allow air or moisture entrapment. Easily compressible, lightweight/installs quickly, stays in place. Do Not Puncture Closed Cell Rod- Outgassing

35 Silicone Non Sag Self Leveling Rapid Cure Hot Pour Standard Modulus Low Modulus Compression Seal

36 Light Gray Horizontal or Vertical Application Low Modulus Requires Tooling Rehab or New Pavements Seals Small Spalled areas in Joint Walls Tack Free in 25 to 90 mins. Full Cure through in 14 days

37 Dark Grey Horizontal Application Only Ultra Low Modulus Neat Seal-No Tooling Rehab or New Pavements Tack Free in 3 hours max Full Cure through in 21 days 6% maximum grade AC/PC Joints???

39 Drums-50 gals of Material 5 Gallon Pails 29 oz. Tubes (6 per case) Store out of direct sun Do not store in freezing temperatures or above 90 F. Keep out of excessive humidity

40 ASTM D-6690: Type I - ASTM D1190 Type II - ASTM D 3405 Type III Low Modulus Type IV - Fed Spec SS-S-1401C FAA P 605-ASTM D-6690 State Specifications

41 Modified Asphalt Based Sealants 2 to 15+ Year Life Cycle Asphalt and Concrete Pavements Different Grades available

43 The pavement MUST be clean and dry

44 Finger Test

46 Water blasting the joint after the saw cut operation is strongly recommended to remove any slurry from the joint. Slurry remaining in the joint from sawing will dry on the walls. Silicone will then adhere to the slurry instead of the clean side wall.

55 After sawing, water blasting, drying, and sandblasting; the joint should be air blasted to remove any debris or sand remaining in the joint.

62 WJE Evaluations

63 Pull Off test No. 1 1 in Pull Off test No. 2 ASTM D 1985 Concrete Block Sample 2 in Bond test Area 1 in 3 in

70 Cold Rod/Hot Rod BACKER ROD 25% Larger than Joint Closed Cell Backer Rod Do Not Puncture Backer Rodbubbling Do Not Stretch Backer Rod

72 Install Longitudinal Backer Rod First, Continuously Through the Transverse Joints and then Run Transverse Rod Continuously Across Pavement Pushing Down Longitudinal Rod at Intersection

75 40 F Minimum Pavement Temperatures Flush Fill, Recessed or Over-band Flush Filled Recessed Flush Filled Beveled Joint

76 3/8 Reservoir Cut Single Saw Cut

78 Non Sag Self Leveling

79 40 F Minimum Pavement Temperatures 1/8 Minimum Recess Requires Tooling

1. Make a knife cut horizontally across the

Hold the piece of silicone firmly and slowly pull

81 1. Make a knife cut horizontally across the silicone 2. Make a vertical cut approximately 3 inches long on each side of the joint 3. Hold the piece of silicone firmly and slowly pull at a 90 angle. If adhesion is proper, the silicone will not pull out of the joint, but will eventually tear cohesively

84 Example of a typical pump used to disperse silicone into joint.

87 Lubricant-Adhesive shall meet ASTM D2835 Installation Above 32 F Install Sealant in Longitudinal Joint First Cut Longitudinal Joint in Center of Each Transverse Joint Install Transverse Joint Continuously Across Sealant Stretch Should be < 4 % Recess Sealant 3/16

96 Design Joint Sealant System for the Expected Joint Movements Select a Joint Sealant Material and Backer Rod Appropriate for the Intended Purpose Ensure Proper Cleaning and Preparation Clean, Dry and Bondable Inspect the Work and Verify its Acceptability

100

101

Design Joint Sealant System for the Expected

Preparation Clean, Dry and Bondable Inspect

102 Design Joint Sealant System for the Expected Joint Movements Select a Joint Sealant Material and Backer Rod Appropriate for the Intended Purpose Ensure Proper Cleaning and Preparation Clean, Dry and Bondable Inspect the Work and Verify its Acceptability See Tech Brief

103

Session 10: Joint Resealing and Crack Sealing 10.1

Session 10: Joint Resealing and Crack Sealing 10.1 Learning Outcomes 1. List the benefits of joint resealing 2. Describe desirable sealant properties and characteristics 3. Describe recommended installation