Concrete Consolidation in ICFs 2
March 23rd, 2010 | Common Troubleshooting, From the Field | Common Troubleshooting, concrete placement, consolidate, Darryl U, kelvin doerr
Last post we went over the proper concrete mix for insulated concrete form walls. Depending on the forms’ size and the concrete core width, the concrete aggregate size and slump should be adjusted accordingly. The ultimate goal is to get the correct compressive strength for the concrete as specified.
Insulated Concrete Form Concrete Placement
The concrete should be placed in 4′-0″ lifts to ensure proper concrete consolidation. Typically if there is more than one concrete pour per project, the walls are poured a story at a time. Concrete is placed in 4′-0″ lifts using several passes around the perimeter of the building plan until either the top of the wall is reached or until the first pour is completed. Concrete should be placed below every window opening through the opening left in the sill of the window buck.
Most Reward builders have found that an overhead boom pump truck is the most efficient method to place the concrete in the Reward walls. With the overhead boom pump truck it is important to slow the velocity of the concrete by reducing the diameter of the hose to 3″ near the end of the line.
During placement, the ICF contractor must keep a close eye all the time on how the concrete is flowing through the forms and around rebar. Be sure the concrete is not getting hung up on rebar or any embedments.
During cold and hot weather, the concrete mix may need to be adjusted to modify its flowability and the rate of concrete placement may also need to be adjusted.
Next post we will cover the actual concrete consolidation and use of internal vibrators with insulating concrete forms.
