Slipform

Like other Flagg houses, the walls were created of stone (in this case Tennessee quartzite) and mortar using a slipform process.

The objective of this study is to evaluate the impacts of vibration and consolidation of modern slipform pavers used in Wisconsin on the air-void structure and air content of portland cement concrete pavements.

On most slipform paving projects, however, small amounts of fixed-form paving or "handwork" are still necessary.

Slipforms of various designs have been used with excellent results.

The slipform is fed with concrete from a crane-carried or rail-mounted bucket.

Vibration may be used ahead of the slipform, but consolidation must be completed as the concrete passes under the form.

Since most horizontal slipforming is against a fixed form support such as rock or earth, the operation is essentially a consolidating-screeding-finishing operation.

However, with recent developments, it is possible to slipform continuous vertical flutings and varying cross sections.

To facilitate and speed construction, Charlie Pankow chose to slipform not only the service and elevator core but also the stairwells -- a more complex operation than the slipforming of the American Cement Building.

New materials such as the by-product PFA helped attain the extra durability required and it is quite common today to slipform with concrete that has 30% replacement of cementicious material and large doses of admixtures.