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Glossary

Armature: The wire and steel which reinforces concrete plaster. May be tied with wire or welded.

Addition Sculpture: Layers of material create three dimension topology. Long-life leads to the fourth dimension. Sculpture that is also a musical instrument includes ferrocement labor in the fifth dimension, automatically. Subtractive sculpture is removal of material from stone or wood.

Econ 3 : Analytical economics from the ferrocement perspective; homes pay for themselves more than once per generation, for many generations, with little or no maintenance. Calculate actual savings with stable monetary units.

Ferro Cement: ferrocement (English), ferrociment (French), ferrocemento (Spanish and Italian), ferrocimento (Portuguese), ferrozement (German). Specific weight example is below.

Center Pole: A post in the center of the tank which can be either temporary or permanent.

Concrete Cure (hardening): Chemical Process. Twenty eight moist days is standard. The time period is effected by temperature. A chemical reaction yields hard concrete. Warmth speeds the process. Completely dry stops the process, it will not start again. Color shade becomes bright. Concrete becomes water proof.

Galvanized: A protective coat of zinc is placed on steel either by dipping the steel in molton zinc or electro plating. Zinc coated steel is often all that is available for the fine outer layers which hold wet plaster in position during application. It is not good to use zinc coated steal for the entire steel content because the concrete slowly dissolves the zinc. Boats are often made with many layers of zinc coated wire packed tightly throughout the ferrocement matrix. The useful life of boat is so much less than an average land based structure that problems caused by zinc do not usually have time to develop. In summary, a little zinc on the outer layers is difficult to avoid and not particularly harmful.

Hog Rings: A "C" with sharp ends is compressed into an "O". Large size is used in agriculture to pierce between pig nostrils in order to lead a pig by the nose. The size of approximately two centimeters is used to fasten steel layers together. Often found at upholstery supply stores.

Metal lath: Also called expanded metal. It is used on one side of a vertical wall and the underneath surface of a ceiling. It can be used on both sides of a vertical wall but is more difficult to force plaster through. Thin gauge is best for ferrocement work (0.045 centimeter). Galvanized expanded metal is less convenient but holds wet plaster just as well as thin gauge lath. This material is very sharp where it has been cut.

Monetary Reform : The act of bringing money into complete compliance with the metric system. One ecologically and socially stable monetary unit equals one kilocalorie. Scientific money is required for calculating economic data through long time, accurately.

Pneumatic hog ring gun cannot attach heavy gauge, galvanized expanded metal.

Plaster Proportions: 2 - 3 dry measures of sand to one measure of cement. Test blocks to determine 550 - 850 kgf/cm2 concrete plaster.

Specific Weight : Depends upon the steel and concrete ratio. This ratio depends upon what is being made and how it is made.

Cement mortar = 2162 kg/cu.m. (135 lbs/cu.ft. )

Steel ............... = 7930 kg/cu.m. (495 lbs/cu.ft. )

Water ............. = 1000 kg/cu.m. (62.4 lbs/cu.ft. )

Example:

Assume a structure which has 50 percent of its total thickness as cosmetic unreinforced plaster outer surface (Two sides @ 25% per side).

Assume an inner armature at 15% steel by volume (for example only).

.5(2162) + .5{.85(2162) +.15(7930)} = 1081 + 1513.6 = 2594.6 kg/cu.m (74.8 lbs/cu.ft. )

If the structure were a boat the steel content would be much higher. Higher yet for a cement racing kayak like those built for experience in college engineering classes.

The racing Kayak might be more like 5% cosmetic finish (10% both sides) and perhaps 25% steel in the armature.

.1(2162) + .9{.8(2162) + .2(7930)} = 216.2 + 2984 = 5146 kg/cu.m (148 lbs/cu.ft. ).

Steel reinforcing bar sizes (approximate diameter):

#2 = 0.64 cm = 1/4 inch
#3 = 0.95 cm = 3/8 inch
#4 = 1.27 cm = 1/2 inch
#5 = 1.59 cm = 5/8 inch

Welded Wire: Mesh is manufactured in many wire sizes and spacing. A wire mesh of ten gauge wire creating fifteen centimeter squares is common for ferrocement. Ten gauge = 0.357 centimeters.

Wire Cloth is galvanized welded wire mesh available in various widths and mesh sizes. A mesh of approximately 1.25 centimeters is used for vertical ferrocement walls on one side. This wire mesh allows easy penetration of plaster yet holds it in place. Premium quality welded wire is also available in this size range.

Sponge float: A trowel with a sponge surface.

Stanchion: A supporting post or pole.