What Are Expansion, Construction, and Control Joints And Why Are They So Important?
A building’s safety and overall structural integrity largely depend on the resilience of its flooring systems. Concrete floors are commonly used in commercial and industrial settings precisely because they’re highly durable. As durable as concrete may be, though, it is not ductile — under enough pressure, concrete will not bend but rather break at its weakest points. These cracks can range in depth, length, and width, but if not properly controlled or accounted for, they can result in total concrete failure.
In order to prevent such a failure from occurring, concrete flooring systems require adequate preparation and spacing in the form of joints, which come in three main categories: expansion, construction, and control joints. Let’s break down the differences and importance of expansion, construction, and control joints.
What to Know About Expansion, Construction, and Control Joints
As temperatures fluctuate, concrete will change in size, shrinking with the cold and expanding with the heat. A concrete expansion joint is designed to allow for this thermal movement/expansion. Heat exchange isn’t the only threat to concrete slabs, however. Concrete may also expand and shift as the soil beneath the floor moves. Heavy loads can also put major stress on your flooring, forcing it to expand sideways. Whatever the case may be, an expansion joint is an intentionally produced dynamic crack that lets slabs move independently to prevent uncontrolled cracking from taking place.
A construction joint also helps prevent cracking caused by concrete movement, but its main focus is on maintaining structural integrity. Construction joints are placed prior to the pouring of a new concrete slab next to an already completed section. When significant amounts of concrete cannot be poured at once, the engineer will strategically break up the pouring process to facilitate construction. Ultimately, construction joints help prevent premature structural failure by allowing for some horizontal movement and restricting vertical and rotational movement.
Lastly, a control joint, also called a contraction joint, is cut into relatively fresh concrete in order to control the direction of cracking as the slab shrinks over time. By strategically placing and spacing out these static cracks, the majority of cracking that occurs will take place inside of the control joints themselves, extending the life and beauty of a concrete floor and increasing its durability.
Making a Joint Effort
Simply put, concrete floors need to breathe — otherwise, they’ll break down. Without expansion joints, construction joints, and control joints, concrete floors would much more quickly buckle under the various environmental pressures they regularly face, including changes in temperature and humidity, heavy machinery and loads, soil shifting, and more. Though each type of joint serves a unique purpose, they work together to improve the strength and stability of a concrete floor and, as a result, a building as a whole.
Of course, even if your floors are properly outfitted with expansion, construction, and control joints, concrete can still crack and experience other forms of damage. Concrete crack repair is one of the many services offered by Kaloutas, along with joint installation and repair, moisture mitigation, concrete polishing and coating, and much more.
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