Concrete is another widely used paving material, like asphalt, which can be used in a multitude of paving applications. Concrete can be the ideal pavement solution from sidewalks to major infrastructure projects. Understanding how concrete is made can be valuable when considering maintenance, concrete repair, and/or a new concrete paving project. Let McConnell & Associates walk you through the process from cement to pavement of concrete.
The Basics of Concrete
Concrete is a composite material consisting of these three main components:
- Cement: Often, Portland cement is the binder that holds the concrete together when it is mixed with water. It is a powder-like substance before it gets wet.
- Aggregates: These solid components include sand, gravel, or crushed stones, which will provide the bulk and strength of the concrete. These components can be adjusted to create different kinds of concrete mixes.
- Water: The water is what initiates the chemical reaction (hydration) that will transform the mixture into a solid mass, once it has fully cured.
- Admixtures: Chemicals or other products added to the mix to alter the finishability and enhance the finished product. Plasticizers or water reducers, accelerator, retarder, corrosion inhibitors, air entrainment, color and fiber reinforcing material to name a few.
On it’s Way to the Job Site
While the components are being mixed in the “concrete truck” it is en route to the job site that ordered it. Once it makes it to the job site, the work of completing the project begins.
- Pouring: Out of the truck, the viscosity (slump) can be adjusted to better suit environmental conditions, or just the overall mix coming out of the truck. This would be the last moment any water can be added to improve the overall consistency of the concrete. The mix is poured into a form, made by framing to make the desired shape and depth.
- Consolidating: Concrete consolidating is ensured by making sure angular rocks within the mix are pushed down into the concrete. It can also be achieved by vibration techniques such as a vibratory screed to create movement within the concrete.
- Finish Work: This is where workers will smooth out the surface of the concrete to ensure there are no imperfections on the surfaces. Also make sure the concrete meets the grade it needs to for proper drainage. Any pockets left on the surface will hold water, which would need fixing later. So this very critical final step in making sure the concrete will be perfect for years to come.
- Joints: Joints in concrete are intentional breaks created to control cracking. Controlling cracking in concrete is key to having a great finished product. Cracking is GOING to happen so having a good joint plan ahead of time is important. Joints can be done during the pour with a jointer or groover. Or can be saw cut after the concrete has hardened.
- Curing: Giving the concrete enough time to properly cure makes sure the finished work is not negatively altered. While the concrete is curing, it gets stronger and stronger. This involves maintaining adequate moisture and temperature conditions for several days at least.
Concrete Repair & Maintenance
It is inevitable however, that over time even the best concrete will develop cracks and other issues due to environmental exposure, heavy loads and heavy traffic. Here are some common methods for Concrete Repair.
- Concrete Surface Repairs: Applying a thin overlay or patching compounds to fix superficial damage to the existing concrete.
- Concrete Patch Repairs: Structural damage may occur inside the existing concrete, which would mean that the section of concrete may need to be replaced. This would include milling up and removing the existing section of concrete, redoing the rebar within, and then pouring in more concrete.
- Crack Injection: An epoxy or polyurethane can be added into a crack that develops in a concrete structure, this will restore structural integrity of the piece. However, the crack may be a sign of other issues, other solutions may need to be explored in the future.
If your projects are beyond these repairs, or these concrete repairs just don’t improve the overall structural integrity of your pavement, Full Concrete Replacement may be necessary.
Also visit our business page on the NKC Business Council here
.png)
