Pouring the concrete floor for our new 26,000 square foot North Wing gallery has been a multi-step process. At the end of August, we shared a time lapse video of the east half of the floor being poured. But, before that could happen, an elaborate support structure had to be put in place for the concrete to be poured onto.
After the layout, the next step was forming and pouring the supporting walls and columns. A plywood deck was erected on a veritable forest of supporting posts.
These posts are set on top of a sturdy base, the tops are leveled and they are kept in place with diagonal bracing. The tops of the posts are interconnected with aluminum structural members. There are main pieces which are set from post to post and interconnecting pieces which connect the mains. There are pieces of wood inset into the aluminum so plywood may be screwed down to create the bottom of the concrete form.
Reinforcing steel is added to the form. This steel connects to the tops of the columns and walls.
The top of the column can be seen.
The steel reinforces the floor. Because the floor needs extra strength under the walls, there is extra steel and extra depth of the concrete.
The shape of the walls can be seen in the steel. The form must be strong enough to support tons of concrete and steel.
Electrical conduit is placed within the floors. Plumbing chases and sleeves are set. There are holes in the walls for heating/cooling ducts. Embeds are set.
These will be accessed from below to hang plumbing or HVAC equipment.
Once the floor was poured and set, the support structure needed to be removed. The posts have a cross shaped nut towards the top. The post has two pins. When the posts are set, the pins lined up with the solid portion of the nut. The structural pieces are carried by the square washer above the nut. When the form is taken down, the nut is spun 90 degrees to line the pins up with the slots in the nut. This allows the form to drop about four inches. The aluminum pieces may be disassembled. Most of the plywood stuck to the bottom of the floor.
Now that the floor is in place, the interior curvilinear concrete walls will begin to be poured.
To learn more about the North Wing expansion project, visit cmog.org/expansion.