Ferrocement

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Ferrocement is a very developed, mature and tested product. Its first use was boat building over 120 years and some cement boats and ships are still floating today. It is very different from normal concrete. It uses only sand as aggregate, (no gravel or stones), and a higher percentage of steel in construction. It is often a mold-less building by making a steel and wire mesh armature that has cement sand pushed into the steel until the steel is fully encapsulated. It is considered labor intensive because of the thousands of wire ties to secure the mesh to the wire/rebar. However in modern time new twisting tools and staple guns can save a lot of that labor. Ferrocement boat constructions strength was demonstrated again and again as a very strong material with off course boats hitting the rocks or the beach to survive this punishment that many other boat building materials failed.

Laminated Ferrocement (LFC)

In the 1970's Martian Iorns developed a system of laminating wire mesh in layers alternating with cement and sand mix to save the labor of tying the mesh. The US Navy did extensive testing including building two ferrocement trial patrol boats one using Iorns diamond shaped expanded metal lath mesh laminated vs standard ferrocement construction. Iorns method was the clear winner as the stronger vessel in pounding high speed trials. While we don't have galvanized expanded metal build to build with in Ecuador, we still use Iorns lamination techniques for some of our building with various wire meshes.

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Ferrocement panels can contain enough steel so they can be flexed to a considerable degree without breaking or opening wide cracks. Pictures below show a three foot span in 1/2 inch thickness with 4 layers of expanded metal lath deflecting 3 inches without breaking.


Both methods are vastly stronger per pound then any current cast concrete technology and remain an ideal shell structure.