I had never heard of this type of construction before reading your post and in an effort to educate myself I found the following article that I thought was very interesting and relevant to this thread. It makes the distinction between rammed earth and PISE construction and explains why PISE is pronouced as a french word.
PISÉ
Builder David Easton recently developed a new, less labor-intensive way of creating a rammed-earth-type home. The process is called Pneumatically Impacted Stabilized Earth - named PISÉ by Easton in honor of the French tradition of rammed earth construction.
PISÉ is another earth-based building material that looks and performs much like rammed earth or adobe. PISÉ has all the environmental benefits of rammed earth, but with one important advantage - its quick-lock forming systems, which speeds up the building process. Trained crews can complete up to 1000 square feet of 18" thick wall per day.
The process, however, is more complex than traditional rammed earth. A mixture of earth, cement and water is sprayed through the oversized hoses of a gunite machine - equipment normally used in the construction of swimming pools - and builds up against the one-sided forms. The carefully controlled mixture is just moist enough to stack up against the form without slumping. The nozzle operator moves along the wall, spraying the PISÉ mix 18-to-24 inches thick and in layer two-to-three feet high. As the wall begins to firm up, any irregularities are shaved off to create a plumb, smooth wall. In 30 minutes to an hour, another two-to-three feet high layer can be added to the wall. Once the PISÉ dries, the forms are removed.
Because the forms against which the PISÉ mixture is sprayed are one-sided, they can be set up and removed quickly. Their open design allows plumbers and electricians to easily put pipes and conduits in place before the wall is cast. And one-sided forms make it easy to incorporate reinforcing steel - rebar - in the wall being sprayed, an important addition for earthquake safety. The addition of steel makes it possible to build taller walls that bear more weight.
PISÉ technology is relatively new, so it is not widely available. It requires sophisticated equipment and meticulous control over mix designs. PISÉ continues to be researched and developed to improve its quick-lock forming systems, versatile soil mixes, soil amendments, and improved delivery equipment.
