NCHRP 784 Major Finding
2/26/2018
W17 Pavement Preservation - Best Practices for Crack Sealing Thomas Kelly, Vice President Crafco, Inc.
NCHRP 784 NCHRP 784 Best Practices for Crack Treatments, Dale Decker 2014 • Surveys, Interviews, Literature Searches • Report Sections • Introduction • State of the Art • State of the Practice • Best Practices • Recommendations #WorldofAsphalt
Major Finding Major Finding
CRACK TREATMENT State of the Practice does NOT reflect State of the Art
#WorldofAsphalt
1
2/26/2018
Why do cracks need to be sealed?
To seal out water. Water entering the ground below the pavement softens the soil, creating a pocket for the water to collect. Next the weight of traffic on the pavement will displace the water. This is how potholes are created. Stopping water from entering into and under the pavement keeps the base stable and the pavement strong. #WorldofAsphalt
Why do cracks need to be sealed? All Cracks Move! Untreated cracks continue to deteriorate. Oxidized edges of cracks lead to erosion. Thermal movement of cracks filled with rocks, sand, dirt and other inflexible debris cause the cracks to grow in size. This deterioration is natural and if left untreated, continues to destroy the pavement. #WorldofAsphalt
Does Sealing Cracks Work? National Center for Asphalt Technology, Auburn University • 2012 Preservation Study Lee Road 159 • 25 Treatments placed in summer 2012 • Crack sealing reduced development of interconnected cracking, and reduced subgrade moisture levels • Crack Sealing as pretreatment improved chip seal and micro surfacing treatment results
#WorldofAsphalt
2
2/26/2018
Progression of Cracking May 2014
Progression of Cracking October 2014
Results: Section L3 Control • Control section has NO treatment applied • Performance measurement is the measured amount of cracking • Changes from treatments will be compared to the control section
9
3
2/26/2018
2Yr Results: Section L5 Crack Seal
100% Less Cracking compared to Control Section
~75% Less Cracking compared to Control Section
• Crack sealing vs. No treatment • D6690 Type 2 • Both routed and unrouted installations (Seal, Fill) • At year 1, there was 100% less cracking • At year 2, there was 75% less cracking than with no treatment 10
2 Yr Results: Section L6 Chip Seal (No Crack Seal pre-treatment)
• NO crack sealing pretreatment • At year 1, there was 100% less cracking • At year 2, same amount of cracking as with no treatment100% of the cracks came through the chip seal At year 2, same amount of cracking as Control Section 12
4
2/26/2018
2 Yr Results: Section L7 Chip Seal (Over Crack Seal pre-treatment)
• WITH crack sealing pretreatment • At year 1, there was 100% less cracking • At year 2, there was 100% less cracking than control
• Compared to--WITHOUT crack seal pretreatment ~100% Less Cracking compared to Control Section!!
• Same amount of cracking as no with treatment 13
5
2/26/2018
2 Yr Results: L11 Micro Surfacing (No Crack Seal pre-treatment)
• NO crack sealing pretreatment • At year 1, 50% less cracking than control • At year 2, 15% less cracking than control
~50% Less Cracking compared to Control Section
~15% Less Cracking compared to Control Section 16
2 Yr Results: L12 Micro Surfacing (Over Crack Seal pre-treatment)
• WITH crack seal pretreatment • At year 1, there was 90% less cracking • At year 2, there was 60% less cracking
• Compared to WITHOUT crack seal pretreatment • Only 15% less cracking at year 2 ~90% Less Cracking compared to Control Section
~60% Less Cracking compared to Control Section 17
6
2/26/2018
Crack Sealing Effects Summary Over the 2 yr Evaluation • Crack Sealing alone • Reduced cracking by 75% compared to no treatment
• Crack Sealing as Chip Seal Pretreatment • Reduced cracking by 100% compared to no pretreatment
• Crack Sealing as Microsurfacing Pretreatment • Reduced cracking by 45% compared to no pretreatment
MN ROAD/NCAT Sections Included ( US -169 and CSAH-8) Crack Seal ( MN 3725- Crafco Roadsaver 522) Mastic ( Crafco Mastic One) Crack Seal/Mastic pretreatment for Chip Seal Crack Seal/Mastic pretreatment for Microsurfacing
Installed August 1, 2016
7
2/26/2018
MnROAD
Oct 26, 2016
National Pavement Preservation Study Northern Sections
CSAH-8 EB and WB Lanes Section 2 (CS&Mastic/ Chip Seal)
MnROAD
National Pavement Preservation Study Northern Sections CSAH-8 EB and WB Lanes Section 11 (CS&Mastic/Micro) October 26, 2016
MnRoad Chip Seal Only
8
2/26/2018
Chip Seal w/ Crack Seal
MN Road Micro Only
Micro w/ Crack Seal
9
2/26/2018
What is crack sealing vs filling? Crack Sealing: • Placement of specialized treatment materials (sealant) above or into cracks using unique configurations to prevent the intrusion of water and incompressible materials into the crack
Crack Filling: • Placement of ordinary treatment materials into low-moving cracks to reduce infiltration of water and to reinforce the adjacent pavement ⁻ PG GRADE ASPHALT ⁻ EMULSIONS & EMULSION/SAND MIXES ⁻ REJUVINATORS
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices • This first factor to know is the project specification requirement. • This trumps all the choices in most cases.
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices Climate Factors
Pavement Factors
• Crack sealants need to remain functional over the range of anticipated pavement temperatures
• Traffic loadings (Volume)
• Determine temperature ranges by using LTPPBind
• Pavement Age/Life Expectancy
• Type of Traffic – Traveling/Parking • Lateral and Vertical Movements • Type of Cracking • • • •
Transverse Thermal Longitudinal Block (Age) Fatigue (Load)
• Density of Cracking #WorldofAsphalt
10
2/26/2018
Crack Sealing Best Practices - Sealant Choices ASTM SPECIFICATIONS • D5078 • Maintenance Sealant • Wide definition of properties often modified for specific climates
• D6690 TYPE 3 • Moderate to cold climate • Moving cracks • Airfields
• D6690 TYPE 1 • Warm to moderate climate • Low movement in cooled climates • D6690 TYPE 2 • Moderate to cold climate • Moving cracks
• D6690 TYPE 4 • Cold and extremely cold climates • Best used with a reservoir rout • Moving cracks
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices OTHER SEALANTS • Fiber Modified Sealants • PG Grade asphalts • Polymer-modified sealant
• Parking Lot Sealants
• Low Resilience Sealants • Designed to relax
• Direct Fire Melter Appropriate
• Appropriate for foot traffic • Withstands steering scuffs • Resists tracking on hot tires
• Less sensitive to overheating • Poor agitation
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices If you get to choose, ask for help from someone you trust as knowledgeable. A good supplier will walk you through several choices and provide help finding the correct specification for your job and climate.
#WorldofAsphalt
11
2/26/2018
Application Options and How to Choose the Best RESERVOIR
CAPPING
There are two basic option for crack sealing. Creating a reservoir in the pavement to accept the sealant, capping the crack, or filling the existing crack opening and applying a cap of sealant on the pavement surface. Both of these applications have their place and can provide a quality seal for the crack. The science of making the right choice of which to choose is what we are going to review. #WorldofAsphalt
Two Primary Applications: Rout & Seal Transverse Cracks Working Cracks
Clean & Seal “Capping” or “Overband” Longitudinal Cracks, High Crack Density Cracks >3/4” and
W17 Pavement Preservation - Best Practices for Crack Sealing Thomas Kelly, Vice President Crafco, Inc.
NCHRP 784 NCHRP 784 Best Practices for Crack Treatments, Dale Decker 2014 • Surveys, Interviews, Literature Searches • Report Sections • Introduction • State of the Art • State of the Practice • Best Practices • Recommendations #WorldofAsphalt
Major Finding Major Finding
CRACK TREATMENT State of the Practice does NOT reflect State of the Art
#WorldofAsphalt
1
2/26/2018
Why do cracks need to be sealed?
To seal out water. Water entering the ground below the pavement softens the soil, creating a pocket for the water to collect. Next the weight of traffic on the pavement will displace the water. This is how potholes are created. Stopping water from entering into and under the pavement keeps the base stable and the pavement strong. #WorldofAsphalt
Why do cracks need to be sealed? All Cracks Move! Untreated cracks continue to deteriorate. Oxidized edges of cracks lead to erosion. Thermal movement of cracks filled with rocks, sand, dirt and other inflexible debris cause the cracks to grow in size. This deterioration is natural and if left untreated, continues to destroy the pavement. #WorldofAsphalt
Does Sealing Cracks Work? National Center for Asphalt Technology, Auburn University • 2012 Preservation Study Lee Road 159 • 25 Treatments placed in summer 2012 • Crack sealing reduced development of interconnected cracking, and reduced subgrade moisture levels • Crack Sealing as pretreatment improved chip seal and micro surfacing treatment results
#WorldofAsphalt
2
2/26/2018
Progression of Cracking May 2014
Progression of Cracking October 2014
Results: Section L3 Control • Control section has NO treatment applied • Performance measurement is the measured amount of cracking • Changes from treatments will be compared to the control section
9
3
2/26/2018
2Yr Results: Section L5 Crack Seal
100% Less Cracking compared to Control Section
~75% Less Cracking compared to Control Section
• Crack sealing vs. No treatment • D6690 Type 2 • Both routed and unrouted installations (Seal, Fill) • At year 1, there was 100% less cracking • At year 2, there was 75% less cracking than with no treatment 10
2 Yr Results: Section L6 Chip Seal (No Crack Seal pre-treatment)
• NO crack sealing pretreatment • At year 1, there was 100% less cracking • At year 2, same amount of cracking as with no treatment100% of the cracks came through the chip seal At year 2, same amount of cracking as Control Section 12
4
2/26/2018
2 Yr Results: Section L7 Chip Seal (Over Crack Seal pre-treatment)
• WITH crack sealing pretreatment • At year 1, there was 100% less cracking • At year 2, there was 100% less cracking than control
• Compared to--WITHOUT crack seal pretreatment ~100% Less Cracking compared to Control Section!!
• Same amount of cracking as no with treatment 13
5
2/26/2018
2 Yr Results: L11 Micro Surfacing (No Crack Seal pre-treatment)
• NO crack sealing pretreatment • At year 1, 50% less cracking than control • At year 2, 15% less cracking than control
~50% Less Cracking compared to Control Section
~15% Less Cracking compared to Control Section 16
2 Yr Results: L12 Micro Surfacing (Over Crack Seal pre-treatment)
• WITH crack seal pretreatment • At year 1, there was 90% less cracking • At year 2, there was 60% less cracking
• Compared to WITHOUT crack seal pretreatment • Only 15% less cracking at year 2 ~90% Less Cracking compared to Control Section
~60% Less Cracking compared to Control Section 17
6
2/26/2018
Crack Sealing Effects Summary Over the 2 yr Evaluation • Crack Sealing alone • Reduced cracking by 75% compared to no treatment
• Crack Sealing as Chip Seal Pretreatment • Reduced cracking by 100% compared to no pretreatment
• Crack Sealing as Microsurfacing Pretreatment • Reduced cracking by 45% compared to no pretreatment
MN ROAD/NCAT Sections Included ( US -169 and CSAH-8) Crack Seal ( MN 3725- Crafco Roadsaver 522) Mastic ( Crafco Mastic One) Crack Seal/Mastic pretreatment for Chip Seal Crack Seal/Mastic pretreatment for Microsurfacing
Installed August 1, 2016
7
2/26/2018
MnROAD
Oct 26, 2016
National Pavement Preservation Study Northern Sections
CSAH-8 EB and WB Lanes Section 2 (CS&Mastic/ Chip Seal)
MnROAD
National Pavement Preservation Study Northern Sections CSAH-8 EB and WB Lanes Section 11 (CS&Mastic/Micro) October 26, 2016
MnRoad Chip Seal Only
8
2/26/2018
Chip Seal w/ Crack Seal
MN Road Micro Only
Micro w/ Crack Seal
9
2/26/2018
What is crack sealing vs filling? Crack Sealing: • Placement of specialized treatment materials (sealant) above or into cracks using unique configurations to prevent the intrusion of water and incompressible materials into the crack
Crack Filling: • Placement of ordinary treatment materials into low-moving cracks to reduce infiltration of water and to reinforce the adjacent pavement ⁻ PG GRADE ASPHALT ⁻ EMULSIONS & EMULSION/SAND MIXES ⁻ REJUVINATORS
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices • This first factor to know is the project specification requirement. • This trumps all the choices in most cases.
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices Climate Factors
Pavement Factors
• Crack sealants need to remain functional over the range of anticipated pavement temperatures
• Traffic loadings (Volume)
• Determine temperature ranges by using LTPPBind
• Pavement Age/Life Expectancy
• Type of Traffic – Traveling/Parking • Lateral and Vertical Movements • Type of Cracking • • • •
Transverse Thermal Longitudinal Block (Age) Fatigue (Load)
• Density of Cracking #WorldofAsphalt
10
2/26/2018
Crack Sealing Best Practices - Sealant Choices ASTM SPECIFICATIONS • D5078 • Maintenance Sealant • Wide definition of properties often modified for specific climates
• D6690 TYPE 3 • Moderate to cold climate • Moving cracks • Airfields
• D6690 TYPE 1 • Warm to moderate climate • Low movement in cooled climates • D6690 TYPE 2 • Moderate to cold climate • Moving cracks
• D6690 TYPE 4 • Cold and extremely cold climates • Best used with a reservoir rout • Moving cracks
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices OTHER SEALANTS • Fiber Modified Sealants • PG Grade asphalts • Polymer-modified sealant
• Parking Lot Sealants
• Low Resilience Sealants • Designed to relax
• Direct Fire Melter Appropriate
• Appropriate for foot traffic • Withstands steering scuffs • Resists tracking on hot tires
• Less sensitive to overheating • Poor agitation
#WorldofAsphalt
Crack Sealing Best Practices - Sealant Choices If you get to choose, ask for help from someone you trust as knowledgeable. A good supplier will walk you through several choices and provide help finding the correct specification for your job and climate.
#WorldofAsphalt
11
2/26/2018
Application Options and How to Choose the Best RESERVOIR
CAPPING
There are two basic option for crack sealing. Creating a reservoir in the pavement to accept the sealant, capping the crack, or filling the existing crack opening and applying a cap of sealant on the pavement surface. Both of these applications have their place and can provide a quality seal for the crack. The science of making the right choice of which to choose is what we are going to review. #WorldofAsphalt
Two Primary Applications: Rout & Seal Transverse Cracks Working Cracks
Clean & Seal “Capping” or “Overband” Longitudinal Cracks, High Crack Density Cracks >3/4” and
