Micro-surfacing with Bruce Wehr.
Bruce Wehr, Sales Representative with AMI, shares his thoughts on a micro-surfacing project using 100% RAP he took part in located in the City of Lancaster, Ohio.
This past year, the city of Lancaster, OH processed their own RAP and created a stock pile to be used in this unique micro-surfacing project. Recently, our team completed the Eddie Road project with outstanding results. The project included crack sealing by a subcontractor, followed by a two course of micro paving and finally, Griffin Stripping came in to replace all pavement markings upon completion.
In Ohio, the City of Lancaster has undertaken an innovative micro-surfacing project that is setting a new standard in pavement maintenance. This project is being done in partnership with Pavement Maintenance Systems, and the mix design was created by Heritage Research Group out of Indianapolis. What makes this project unique is the city using RAP aggregate for the first time instead of the limestone normally used in Ohio projects. This type of aggregate is cheaper for the city to produce, as it uses accumulated aggregate from mill and fill projects throughout the city.
Let’s take a look at how this project is coming together.
Why Choose Micro-Surfacing or Pavement Preservation For Your Roads?
Pavement preservation is important because, overtime, hot mix asphalt ages and the asphalt actually loses its ability to hold together. Putting a treatment such as micro-surfacing (as seen on this project) on the surface of the old hot mix, seals it off and extends the life of that hot mix.
Most micro-surfacing, depending on the condition of the road and traffic, will extend the life of the pavement between 6 to 8 years or longer. Another benefit of micro-surfacing is that its a thin overlay, so you do not have to do any adjustments to curb and gutter storm sewer outlets, water valve boxes, and more!
Micro-surfacing has been around for a long time and is a cold process. The chemistry involved with the emulsion is designed to force the water out of the mix, and you can usually resume regular traffic in about an hour after a micro-surfacing project is complete!
- Loss of friction
- Uneven surface profile
- Lack of uniform color for restriping
- Increases skid resistance
- Improves color contrast between pavement and striping
- Restores surface characteristics
- Protects the structure from moisture intrusion
- Protects the structure from oxidation
- Maintains drainage patterns and curb reveal
- Restores road profile (within limitations)
- Resistant to rutting and shoving
Road Selection Process
When you’re selecting roads for micro-surfacing, you want to look at a roadway that has a good longitudinal profile and a good cross slope. If there is a roadway section that does have a lot of alligator cracking ,but no subgrade issues, you can do a cape seal, which is where a chip seal is put down to seal all the cracking and then micro-surfacing over that! If there is a road with some minor rutting, like at intersections, there are other treatments that can be used with micro-surfacing, if it is not severely cracked.
The process of bringing these micro-surfacing projects to life is done in a way that ensures everyone involved is informed, prioritizing safety, and feels understood. The team works with the local agencies, cities and counties in the state preparing specifications, talking about the projects, and then physically going out and reviewing the roads that have been selected to ensure they are good candidates for construction.
The team makes sure to sit down with the agency or the owner 1 on 1 to walk them through the process and explain to them the benefits. Once that is done, it creates a very successful project.
Benefits of Micro-Surfacing
Pavement preservation is highly cost-effective. Every study that has been done of micro-surfacing, chip seal, or crack seal, reveals that these are all treatments that help extend the life of that pavement. You want to preserve that asphalt as long as possible in a good condition to carry the traffic and keep cracked pavement, failure of the pavement, and other issues at bay. We want to keep water intrusion out of the pavement itself along with the subgrade, and this is one of those treatments that assists with that.
When we look at these projects, a couple things need to happen: If there is cracking in the existing pavement, that needs to be addressed with a crack sealant. The other thing is pavement markings. If the pavement markings are thermo-plastic, those markings need to be removed before placing the micro-surfacing. Then, just before laying down the micro-surfacing, the construction crew will go in and broom the road to clean the surface. We want to make sure that all the dust, dirt and loose aggregate is off the surface so that we can create a good bond with that existing asphalt when we place the micro-surfacing on the road.
When doing a micro-surfacing project, you need a yard to lay down the aggregate. You’ll have storage tankers for emulsion and water, you’ll need a place to clean equipment out. So when you are looking at these projects, you’ll need a yard location to be able to do that type of work. This is something that cannot be done out on the road itself. And it is usually the contractor that finds these locations when they did the project. We just so happen to be with the city of Lancaster processing the aggregate to be used that gave us the yard here that was used for their projects.
Micro-surfacing is a part of the AMISEAL™ family. AMISEAL™ is the core of pavement preservation, including projects such as micro-surfacing, chip seal, crack seal, cape seal, fog seal, and more!
When looking at the performance products in the AMISEAL™ family, the greener nature of these pavement preservation methods is speaking the language of sustainability!
To learn more about our performance product porfolio, visit our website at