Large construction projects use massive amounts of concrete which is delivered direct from the batching plant to the job site. Once the concrete delivery trucks begin arriving, the offloading and pouring starts; and once it starts the finishing work must keep pace with the delivery.
Once the concrete begins to pour into the forms; workers wielding a device from Chicago pneumatic in New York City called a concrete vibrator set to work. Freshly poured concrete is full of trapped air bubbles, if left undisturbed in the mix, the cured concrete slab or wall could easily be weakened by their presence.
Small concrete pours rarely need to be vibrated but larger pours and deep pours of concrete most certainly do. For this reason there are a number of different size vibrators manufactured, some using electric power, other operate from a compressor. Many construction companies will have various size concrete vibrators at their disposal, what is most important is that the vibrator have a vibrating device which is long enough to get all the way to the bottom of the pour.
A concrete vibrator is not a very complicated device; basically it uses an eccentric weight which spins very fast, some as fast as 10,000 rpm. It is the vibrations set off by this rapid spinning that break up the air pockets, dispersing them and bringing them to the surface. A vibrator from Chicago pneumatic in New York City is a necessity when the concrete that is being poured is low slump. Low slump concrete uses minimal amounts of water in the mix so it’s important to give it a complete vibration otherwise air bubbles will be in the cured concrete.
When selecting the appropriate concrete vibrator there are only a few things to consider; the size, the speed of vibration and whether the vibrator will be internal or external. Small pours can be accommodated by smaller, electric powered vibrators with a short probe, for larger and deeper pours a high speed machine with a longer probe is required as the task must be completed in a relatively short time.
Many pours are vibrated with an internal machine which is inserted into the concrete, for very large slab pours where the objective is to have a smooth, flat finished pour; an external vibrator is attached to the forms, thereby vibrating the entire slab. Click here for more information.
