Most of Slab Specialists concrete is pumped from concrete truck to slab. The pump operator must put the concrete as near as possible to its final place BEFORE vibrating the concrete. "Dragging" the concrete into position causes segregation of sand and cement, weakening the concrete.
Delivered concrete has up to 12% air trapped in it. If the air is not removed, concrete will only be half as strong. Air is removed by vibrating and compacting the concrete, only when it is in position and only for the correct amount of time, and only with the correct technique.
The vibrator operator has a very important job to get this right.
Placing must be done at the correct speed, too fast and the compacting crew will not be able to keep up, too slow and the mix will stiffen making placing very difficult.
Water content is critical to the finishing and curing process. The longer concrete is given to dry the stronger the finished product. When required, Slab Specialists placers use a curing agent to maintain moisture in the slab while it is being placed. If the surface is allowed to dry out too fast it will be weakened and more likely to crack.
Slab Specialists only use professional concrete placers to ensure concrete is placed correctly.
Refer to the technical section on Curing Concrete and Control Joints for more information.