Grade beams are used in footing construction when a full footing is not needed, but spot footings are inadequate to the task of distributing the load carried by the foundation piers. Grade beams are a kind of rebar column structure (evenly spaced bands with continuous bars) that are laid horizontally in trenches or forms beneath the foundation piers. You pour grade beams much in the same way that you would pour any type of concrete; however, there are some unique considerations to keep in mind.
Pour at one end of the concrete beam. Aim the concrete chute from the truck (or the end of the hose from the pump) and release the concrete. Do not move the chute or hose forward until the area of the form below it is filled with slightly more concrete then you actually need to reach the finished height of the grade beam.
Vibrate the concrete thoroughly. For every 6 feet of pouring, "hit" the concrete with the vibrator. Hitting the concrete means to insert the vibrator fully into the concrete in several places. When the concrete is vibrated, the level of the concrete will fall. Add more concrete if it goes below the height that you need for the finished grade beam. Vibrating concrete gets rid of any air pockets and makes sure that the concrete works its way fully around the rebar in the form.
Complete pouring to the concrete height needed in the grade beam. Grade beams do not need a trowel finish. You can roughly level and finish the beam using a small piece of 2x4 cut to slightly less than the width of the beam. Move the 2x4 in a back-and-forth motion across the surface of the concrete to level it off, do this the entire length of the beam.