If we free our minds from the constraints of stiff, rigid, inflexible formwork for concrete, any previously difficult jobs are practical and many heretofore impossible jobs can be done. The use of a flexible and permeable form a fabric opens interesting possibilities. A highly permeable fabric in the shape of a bag or similar enclosure can act as a form for concrete or grout equally as well above ground, where air is displaced from within the form. The solidified mass can easily be made in many different configurations. Equally important is that the empty form can be placed in difficult-to-reach locations and then filled by pumping after it is properly positioned.
The major variables to be considered in this type of application of the use of construction fabrics are the following: type of fabric to be used (depends on the desired permeability of the fabric, the viscosity of the concrete fill material, the ease of making joints and closures, the desired stiffness of the form before filling, the final shape of the solidified mass of concrete or grout, the cost, and the danger of infringement); placement of the fabric form insofar as construction method, type of labor and inspection before filling are concerned; design of the concrete filling the fabric form; accessibility, time and cost of placing concrete to fill the form; manner of curing the concrete after placement; inspection of completed installation to check on the adequacy of the work and to see if further modifications are required; and the setting up of a possible long-term monitoring system if desirable.
