Crack Sealing & Filling. Crack Sealing Why, Where, & How. 5 Benefits of Crack Sealing. Crack Sealing - Overview. Repair Many Types of Cracks

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1 Crack Sealing Why, Where, & How Dennis Roberts Remac Asphalt Maintenance, Inc. Freeman, Virginia Crack Sealing & Filling Crack repair treatments are an important part of all preparation work and should never be overlooked Crack treatments are consistently the lowest cost option and provide the highest benefit 5 Benefits of Crack Sealing Crack Sealing - Overview 1. Extends pavement life 2. Restricts water penetration into the underlying base and subbase layers 3. Used in conjunction with surface treatments to retard reflective cracking. 4. Material bonds to crack walls and moves with pavement 5. Cost-effective use of dollars over time compared to other pavement maintenance techniques Why and when? Pavement evaluation Determine if Crack Sealing (working cracks) or Crack Filling (non-working cracks) treatment is needed Determine pavement temperature (high/low extremes) Select product Proper application/equipment What cracks to treat? All cracks soon after they appear any crack opening will allow moisture Water penetration into pavement foundation (subbase) New industry standard all cracks 1/8 to 1 ½ Repair Many Types of Cracks Standard Crack treatments will not address all the defects Removing and replacing is costly and time consuming, so it is important to recognize good and bad candidates for crack filling

2 Bad Candidates for Crack Sealing Excessive deterioration Cracks turned to Potholes Replacement Recommended Treat Cracks Early Or they could become like this

3 Or like this Too Many Cracks for Sealing Good Candidates for Crack Sealing Can be filled effectively Block Cracking Random Cracking

4 Good Candidate Minimal Deterioration Pavement Joints are Good Candidates for Crack Sealing Concrete cracks can be sealed Water Intrusion is an Indicator Sealing Prevents Water Intrusion

5 Incompressible dirt and debris Incompressible Intrusion Seal joints between asphalt and concrete What cracks to treat? Don t forget edge joints Crack Sealing Treatment Cap Fill and Squeegeed Overband Methods Use: In thermal cracks Routed reservoirs Pavements in good condition- >20 transverse crack spacing, minor other cracking

6 Squeegee cracks or use swivel shoe to overband? If you intend to overlay the area being crack sealed within the year: Area should be squeegeed to flatten the overband to a film thickness This applies to either hot mix or slurry mixes Squeegeed overband will be wider and will not appear as neat as the swivel shoe application Using the V shaped Squeegee on cracks is more costly due to the extra labor involved with using the squeegees Swivel shoe sealed crack 5 years later If you are not intending to overlay for more than a year: Overband using only the swivel shoe Using swivel shoe only (without squeegee) is less costly V shaped Squeegee sealed crack 5 years later 5 year old Squeegeed Crack 2 Year Old Swivel Shoe Cracks 2 Year Old Swivel Shoe Cracks

7 2 year old V Squeegee Cracks on Limited Access Road 4 Year Old Swivel Shoe Applicator Filled Crack Rout Size Recommendation Routing Rout at least 1/8 from each crack face Keep centered over crack Reduce spalling by using as many cutters as possible Cracks being routed on demo project Routing shows loss of larger aggregate along edges

8 Routed crack with missed area along the top Routed with missed area creating additional crack Routed Crack prior to filling Crack after routing and filling with V shaped Squeegee Reasons to Rout Cracks 1. Various studies show that there is greater chance of sealant success if cracks are routed prior to sealing 2. Crack routing involves cutting through the crack to provide a uniform rectangular reservoir in which the sealant is to be placed 3. Cutting a reservoir above the crack allows adequate sealant expansion and contraction 4. Routing creates uniform and smooth edges, thus allowing the sealant material to adhere better with the asphalt pavement More reasons to Rout Cracks 5. The reservoir ensures that the proper amount of sealant penetrates the crack 6. You can fill the reservoir flush with the surface or a little below the surface which helps when overlaying within a year of crack sealing

9 Disadvantages of Crack Routing It turns a smaller crack into a larger crack It can fracture the pavement around it The larger reservoir requires using more material When the router misses the crack you are trying to follow, it creates an additional crack It is more costly due to more labor, equipment, and material needed It inconveniences the traveling public for a longer period of time due to extra time required routing the cracks Cleaning and drying of Cracks Before placing sealant, all cracks must be thoroughly cleaned Crack cleaning is essential since most failures occur as a result of cracks not being cleaned properly For drying, a hot compressed air heat lance is used For proper crack sealing the crack must be free of moisture Airflow from the compressor should be free of oil and moisture Cleaning with Heat Lance Lab Manufacturing Model C Heat Lance Crafco Heat Lance Crack Sealing Truck with application machine behind

10 Hot Pour Crack Sealer being applied on routed crack Crack Sealer can be applied with one of several types of shoes V Shaped Crack Squeegee Using V Squeegee behind applicator Flattening with V Shaped squeegee Sealant Application - Overband Maximum 1/16 thick Maximum 2 overband on each side of crack Overband- best performance (SHRP/FHWA)

11 Control Panel on melting machine Hot Pour Crack Sealer applied through heated hose Recommend Overband (Non-Rout/Clean & Fill) Detack applied to filled cracks Crack Sealer followed by Detack Application Crack Sealer and Detack applied

12 Not recommended Why Seal Cracks? Prevents water intrusion into subbase Prevents incompressible intrusion Improves ride quality smoothness Slows down pavement deterioration COST-EFFECTIVE Summary Thank you Cracks are inevitable, and neglect leads to accelerated cracking and potholing, further reducing pavement serviceability. Questions? (FHWA-RD ) Contact Me: Dennis Roberts C: O: