Commercial Site Visit: Concrete Form Wall

          This past week a section of concrete wall was formed and poured at the new Virginia Tech Dining Hall.  I last visited the site on Sunday 11/28 and was amazed to find that when I revisited two days later, a full 30'x15' set of forms had been erected in preparation for pouring a concrete wall.  The forms were plywood forms with dimensional lumber fastened with removable clamps and form ties to hold the forms together.

11/28/10 Before forms were erected.

12/1/10 Finished forms.

          As you can see in the above picture there was a recent heavy rain.  This can cause some problems with the curing of the concrete which was to be poured later in the afternoon.  If the forms were extremely wet when the concrete was poured, the excess water could effect the cure time and cause variances in the strength of the concrete.  To help prevent this much of the forms were covered in tarps.  Also seen in the above photo are wooden walkways built around the forms.  These walkways allow workers to walk around the edges of the forms and vibrate the concrete as it is being poured to release air pockets.  If the concrete is not properly vibrated, small air pockets can develop creating voids in the concrete and severely compromising the structure.

Walkways and tarps around the forms.