When starting your concrete project, you’ll likely hear one of the following terms from your contractor: expansion joints, construction joints, or concrete contraction joints. It’s important that you understand these terms and what they mean in regard to your driveway. Continue reading as we break down just what these terms mean and what their purposes are.
In general, concrete joints are used to prevent cracking or to enhance concrete performance. Their main purposes include:
1. Separating concrete from other structural pieces
Expansion and isolation joints are used to isolate the concrete itself from other structural components. As the temperature changes, your concrete will expand and contract. When the weather shifts, expansion joints allow for movement amid adjacent structural parts, and also restrict movement when necessary to decrease the possibility of cracking. Isolation joints block the concrete from expanding into other structures, like posts or pipes, that may be placed in or near the concrete.
2. As a guide for the predetermined layout of the joints
Construction joints are used to map out the individual placement of joints. They transfer flexural stresses created in the slab from external weight, as well as allow for displacements between each side of the slab. These joints are typically seen in precast concrete and must prevent rotational or vertical displacements, while simultaneously allowing for horizontal displacement due to shrinkage and thermal movement.
3. Controlling the areas of concrete where cracks usually occur
Control joints, or concrete contraction joints, are specifically used to prevent cracking in areas of your concrete that typically crack. This type of joint is the most common, and it controls cracks by creating a weak spot in the driveway and regulating its dimensional changes. Concrete contraction joints are usually arranged in perfect squares within a straight line.
At Port Aggregates, you can rest assured that our team of professionals will be happy to answer your questions and help you choose the right product for your next project so that your concrete can survive the rapidly changing Louisiana weather. We proudly serve 26 locations around Louisiana, including Lake Charles, Leesville, Lafayette, Jennings, and more. Contact us today to request a quote for your concrete project!