Curbs and Gutters
Curb and Gutter Systems are an Essential Support for High-Traffic Pavement
Curb and gutter systems are vital pieces of infrastructure, which is why you’ll see them everywhere. They can be made from asphalt or concrete, though here along the Gulf Coast, concrete is king when it comes to curbs.
In most cases, curb and gutters are laid down in conjunction with a larger pavement project, such as road construction. Depending on the project’s scope, it will take several days to prepare the project site, pour the concrete, finish it and cure it. Along the way, the pavement team must adhere to extremely tight tolerances to ensure compliance with local build ordinances and to ensure a long-lasting result.
Three Reasons Why Curb and Gutters are Necessary for Pavement Projects
There are plenty of reasons why municipalities invest in curb and gutter systems. Three of the most important include:
- Pavement reinforcement – Curb and gutter systems reinforce the pavement’s edges, which is where the pavement tends to be weakest. This will protect the pavement from cracking and damage due to excessive load bearing.
- Efficient runoff drainage – Without gutters, it would be impossible to reliably remove runoff from streets. Their slight grade captures rain, leaves, and other debris, and helps maintain clean and clear roads.
- Providing borders between road and pedestrian traffic – Curbs help motorists and pedestrians quickly visualize where motor and foot traffic go. Curbs also provide a physical barrier between vehicles and pedestrians. Together, this adds up to safer roads.
Why is Concrete the First Choice in Curb and Gutter Construction?
Curb and gutters are important pieces of infrastructure, but why are they made from concrete? The only viable choices for curb construction are concrete and asphalt, and in our part of the country, concrete is the clear winner. Here’s why:
- Concrete is extremely durable – Concrete possesses superior compressive strength and can be effectively reinforced against tension. Its excellent load bearing capacity and ability to handle most types of weather make it an ideal choice for high traffic areas like streets. Its durability is also important for curb and gutter systems, which take the occasional low-speed impact.
- Concrete handles exposure to water well – Compared to asphalt, concrete is more water resistant and can be waterproofed with additives. Once waterproofed, concrete is the ideal curb and gutter material.
- Concrete requires little maintenance – If properly installed, concrete curb and gutter systems will last decades, even with little maintenance. Sealing the concrete can extend its life further, and the occasional crack may need filling, but concrete is a true low-effort material to maintain.
- Concrete provides excellent hydraulic efficiency – Concrete’s well-rounded durability means it will retain its shape even when subjected to intense forces. This is a valuable trait to have in drainage systems, as it ensures optimal hydraulic efficiency (flow).
What Does the Curb and Gutter Construction Process Entail?
Curb and gutter systems can be made in a couple of ways. There are curb-forming trucks that can lay down a smooth, continuous line of concrete curb without the need for formwork. Instead, the pavement team stakes out the curb’s boundaries and runs a string through them to guide the curb former as it deposits concrete.
However, most pavement contractors still rely on traditional formwork and hand-finishing to complete a curb project. Here’s what that process looks like:
- Marking and excavation – Before any concrete work begins, the project site must be marked to specifications. This is done with flags and with powder that shows up well on grass and soil. The markings are used as a guide for excavation, and an excavator is used to move the marked dirt.
- Setting the concrete formwork – Once extraction is completed to the specified depth, wooden formwork is laid down. This formwork acts like a mold for the new concrete, ensuring it is shaped properly. Steel reinforcement is also laid out during this time.
- Pouring the concrete – The concrete is then poured into the formwork, evenly and from a low height to avoid trapping air in the mix. For curb and gutter systems, the preferred concrete mix is a high-strength one. Once the concrete is poured, it is agitated using vibration. This removes any trapped air, which would compromise curing.
- Finishing the concrete – The concrete is graded and textured where necessary. Texturing is done with a broom and provides extra traction for pedestrians.
- Curing the concrete – It will take weeks for the concrete to completely cure, but it will be ready for vehicle and pedestrian traffic within days. Proper curing relies on proper concrete mixing and moisture control, so chemical curing agents are added to support optimal moisture levels.
- Jointing the concrete – Like concrete flatwork, concrete curb and gutter systems must be jointed to prevent cracking due to thermal stresses. Curb and gutter joints must continue the joint pattern established on the adjoining pavement to prevent stresses between curb and pavement.
As you can see, a lot of work goes into every stretch of curb. Given the labor and tolerances involved, property owners and cities prefer to work with an experienced concrete contractor.
Precision is Critical for Curb and Gutter Projects, so Work with an Expert Team
If your property needs curb and gutter work, it’s important that you bring in an experienced pavement contractor to do the job. An expert team will abide by best practices to ensure long-term durability and performance from the concrete. For example, an experienced pavement team will be able to spot potential issues, such as shifting or corrosive soils, that could cause significant project delays.
If remaining on time and on budget are top priorities for your project, the concrete construction experts at American Parking Control are ready to help. We’ve built out hundreds of miles of curb in the nearly 40 years we’ve been in operation. That experience gives us the edge with every curb and gutter project, and we can bring that experience to your project as well.