Ferrocement
From Wikipedia, the free encyclopedia
Ferrocement is both a method and a material used in building or sculpture with cement, sand, water and wire or mesh material - often called the thin shell. Thin shell ferrocement offers strength and economy and has a broad range of applications which include home building, creating sculptures, or building boats and ships.
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[edit] Construction
The desired shape is built from a multi-layered construction of chicken wire, and if needed reinforced with steel wire or steel bars. Over this finished framework, an appropriate mixture of cement, sand and water is spread out. During hardening, the ferrocement is kept moist, to ensure the cement is able to set and harden.
The wall thickness of ferrocement constructions lies in general between 10 and 30 mm, depending on the span. It can take up to one month before the ferrocement sheet reaches its final strength.
[edit] Application
In India, ferrocement is used often because the constructions made from it are better resistant against earthquakes.
In the 1970's, designers adapted their yacht designs to the then very popular backyard building scheme of building a boat using ferrocement. Its big attraction was that, for minimum outlay and costs, a reasonable application of skill, an amateur could construct a smooth, strong and substantial yacht hull.
[edit] Advantages
The advantages of a well built ferrocement construction are the low weight, maintenance costs and long lifetime in comparison with steel constructions. However, meticulous building precision is considered crucial here. Especially with respect to the cement composition and the way in which it is applied in and on the framework.
When a ferrocement sheet is mechanically overloaded, it will tend to fold instead of crack or rupture. The wire framework will hold the pieces together, which in some applications (boat hull, ceiling, roof) is an advantage.
A ferrocement construction has 10 to 25% of the weight of a comparable construction made of bricks.
[edit] Disadvantages
The disadvantage of ferrocement constructions is the labor intensive nature of it, which makes it expensive for industrial application in the western world.
