After decades of service providing customized material flow solutions, one of the most common questions we’re asked at Deca Vibrator Industries, Inc. is “how concrete vibration works.”
It’s a fair question. Confusion can easily arise due to the fact that concrete vibration applications are not all the same and different forms require different consolidation techniques. Fortunately, since we supply a broad range of concrete vibrators and processing equipment, we possess the knowledge and experience to match the right frequency and amplitude to just about any concrete compacting application.
To give you a basic understanding of the overall process, we’ll discuss the common points of concrete vibration and how the process effectively helps eliminate unwanted air bubbles, honeycombing and the negative effects of cold joints.
Concrete Vibration 101: How to Consolidate Concrete
When concrete is freshly poured — especially low slump concrete or another type that has a less fluid mix — thousands of air bubbles are trapped in the mix. Now, if the concrete were left to settle on its own, these air bubbles would result in weak spots where the concrete could honeycomb and become unstable.
To avoid this from happening, a concrete vibrator can be used on the freshly poured mix to release a good majority of air bubbles and cause the mix to consolidate in a more uniform and strengthened manner.
While many consider concrete vibration more of an art than a science, there are some fundamental rules to keep in mind.
Before pouring concrete, there are some preparatory steps to take so that the mix sets properly. Of course, you want to be sure that you have enough trained workers, a leak-proof form and the right type of vibratory equipment with sufficient power sources — and even backup equipment in the event that anything goes wrong.
To make the right choice as to which type of concrete vibrator to use, here’s a brief look at the three primary vibration methods:
- Formwork vibrators: Usually powered by pressurized air or electricity, formwork vibrators are attached to the outside of your form, typically at about six-foot intervals. They’re a favored form of vibration for precast concrete work.
- Surface vibrators: While surface vibrators — also referred to as jumpers — do work on the surface of your pour, they have reduced effectiveness on pours that are over a half-foot in depth. However, when appearance is a priority, surface vibrators do a good job of leaving your pour with a noticeably smooth finish.
- Internal vibrators: Probably the most popular form of concrete vibration is the use of internal vibrators. Designed to be handled by a single trained operator, internal vibrators are usually air-driven or electric. The basic process involves a quick insertion followed by a slow withdrawal, during which trapped air bubbles are quite effectively released.
For the best concrete pour results, you want good consolidation to occur. In basic terms, consolidation is the process by which you work to remove as many trapped air bubbles as possible from your freshly poured mix. Remember that while it’s impossible to remove all air bubbles, experience proves that under-vibration is more common than over-vibration, so consider these best practices when inducing consolidation.
For the most popular internal vibrators, the key is to quickly insert the vibrator head followed by a recommended minimum of a one-inch-per-second withdrawal. Keep an eye on how the concrete responds. And if you’re pouring over a previous layer, try to insert the vibratory head at least six inches into the earlier layer to prevent cold joints from occurring.
Deca Vibrator Industries, Inc. for All Your Cement and Concrete Consolidation
Regardless of the type of concrete pouring you’re doing, having the right concrete and cement vibrators is key to making the job a success. That’s why, at Deca Vibrator Industries, Inc., we offer a wide range of concrete vibration equipment to fit all of our clients’ needs.
We know our reputation is directly tied to our customers’ satisfaction. And since 1980, we’ve been building our reputation as an industry leader in material flow equipment one satisfied customer at a time.
For more information and answers to all your concrete vibration questions, contact us today.