How to Anchor To Asphalt

Bolthold Asphalt Anchors & Grout

There is a difference between the anchors required for concrete and asphalt surfaces. Using the correct anchor will result in top-notch performance while keeping your structure safe and secure. Bolthold Asphalt Anchors and the compatible adhesive grout are a game changer for many temporary or long-term asphalt applications.

Continue reading to learn how asphalt anchors work, the difference between concrete anchors and asphalt anchors, how to install and remove the anchors, and common asphalt anchor applications. To get started, watch the video below to gain a better understanding of why the anchors you choose will make the difference between a job well done and a job that has to be redone!

(Courtesy of Bolthold Asphalt Anchors https://www.youtube.com/channel/UCK5NAgcecD4hDfkP_U_Z4Tg)

Asphalt Anchors vs. Concrete Anchors

Asphalt Anchors

Asphalt is a material that "creeps" under continuous pull stress. Creeping is when the asphalt experiences deformation and fractures due to too much pressure. High temperatures and high pressures affect creeping even further. Asphalt is about 20 times more yielding than concrete. Typical concrete can resist 4,000 psi of pressure whereas asphalt can resist approximately 200 psi. Anchors specifically designed for asphalt resist the pull forces depending on the size of the anchor.

Concrete Anchors

The yield strength of concrete vs. asphalt is a large factor in why the two materials require different anchors. When anchoring to asphalt, concrete anchors should never be used. They do not apply constant pressure to the asphalt. Both concrete expansion anchors and wedge anchors will loosen their grip in the asphalt and fail in a short amount of time.

How Asphalt Anchors Work

Bolthold anchors also known as chemical anchors, use Bolthold adhesive grout that binds with the asphalt and gravel. The grout creates a stress-free bond that maintains a strong and secure connection that does not weaken over time. Fasteners Plus offers the EPX2 cement-based grout and the EPX3 epoxy resin cartridge that seals the anchors with ease.

Additionally, the asphalt anchors are mounted flush with the asphalt surface. Each has a header at the top of the anchor that prevents it from dropping below the surface or being pulled up into the mounting plate. The zinc-plated anchors and molded plastic anchors are both great options for getting the job done. Kits that include the asphalt anchors and grout are excellent for smaller jobs.

Grout for Asphalt Anchors

The EPX2 grout is the most cost-effective option for installing asphalt anchors. This expanding anchoring cement begins as a powder and activates once you add water and knead the mixture. The EPX2 option is available in resealable bags sold in 6-pack quantities or 10 lbs. tubs.

The EPX3 epoxy grout is a two-part acrylic resin. It is packaged in a single cartridge. The cartridge is supplied with one static mixing nozzle that fits on the thread at the top of the cartridge. It discharges an accurate mix of the two resin components. This eliminates any manual mixing.

The Best Way to Anchor into Asphalt

Listed below are the summarized steps to take when installing Bolthold asphalt anchors with the EPX2 cement-based grout. For detailed step-by-step instructions, follow the asphalt anchor installation guide.

1. Drill a hole into the asphalt surface to the diameter and length specified in the chart below.

2. Use compressed air or a blower to clean dust from in and around the hole.

3. Pour a pre-measured volume of water into a mixing container. The quantity of grout created varies depending on the amount of water used and the consistency of the mixture. Use the table below to estimate the amount of water and grout required for four anchors.

4. Slowly add the EPX2 grout powder to the water and stir continuously. The consistency of the mixture should be syrup-like for best results.

5. Slowly pour the grout mixture into the hole. Make sure the adhesive fills each hole from the bottom to a little above the asphalt surface. Not filling to the top of the hole will significantly weaken the anchor and the asphalt. To eliminate air pockets, poke the grout with a thin tool.

6. Push the anchor into the hole with a slow down-up motion so the entire length of the anchor is covered by the mixture. Within 15 minutes, the anchoring grout will begin to cure. The full cure time is about 1 hour. To avoid issues, wait 2 hours before exerting a pull load or a heavy torque on the anchors. Lastly, wait 24 hours before performing a pull test on the anchors.

How to Attach a Structure to Asphalt

1. Remove the bolt and washer from the anchor. This can be done 15 minutes after the grout is poured as long as the outside temperature is 75°F or higher. 

2. Make sure the plate you are attaching is flat. Align the holes in the plate with the anchors.

3. Insert the washer and the bolt and tighten. Make sure you don't exceed the torque. The required torque amounts are listed in table 1. (Do not use an impact wrench to tighten the bolt).

How to Remove Asphalt Anchors

In situations where your anchor needs to be removed, the best time to do this is immediately after installation. It is much easier to remove the anchor before the grout has fully cured. This would be within 15-60 minutes after pouring the grout. 

The best way to remove the fastener is to use a socket or wrench. Over-tighten the bolt to the point where the entire anchor will rotate and break away from the adhesive. As the anchor rotates, also rotate it counterclockwise. This method may pull it out. If this does not work, use a nail puller or two large flat screwdrivers. Place the tool under the anchor's head to lift it out. 

If the grout has fully cured by the time you are ready to remove the anchor, overtightening the anchor, may cause the head of the fastener to break off the body. If that happens, you can use a metal drill to drill out the body of the anchor.

Common Asphalt Anchor Applications

When deciding on whether to secure a structure using Bolthold asphalt anchors, it is important to understand how stable the object is on its own. If the object/structure stands solidly by itself, you can load the anchors at 80% of their pull rating. If the object applies a static pull force on the anchors just as it stands, limit the load on the anchors to 20% of the pull rating. View table 1 for each anchor's tested pull rating. 

Common Applications:

• Bike Racks
• Signs
• Machinery
• Carports
• Speed Bumps
• Road Delineators
• Tents/Shelters
• Gates
• Railing