Understanding Stabilized Earth Block Construction Using the Cinva-Ram
Nils Gore, Assistant Professor
University of Kansas School of Architecture and Urban Design


These web pages are a documentation of some research into stabilized earth block construction I've done with undergraduate architecture students over the past few years. I started this work in a Materials class I taught for sophomore architecture students at Mississippi State University School of Architecture (MSU), and since moving to the University of Kansas School of Architecture and Urban Design (KU), have resumed it here, in a design studio for third-year undergraduates.

The Cinva-Ram is a manual block-making machine developed by Raul Ramirez of the Inter-American Housing Center (CINVA) in Bogota, Colombia. It uses the principle of compression in making building blocks and tiles from a number of materials, including common soil. The ram is a steel box with a bottom that moves up and down. The mix is placed in the box, and a steel lid is placed on top. A lever is pulled to one side and the bottom moves up, compressing the mix against the fixed top. The lever is released, the top removed, and as the lever is pushed into the opposite direction, the bottom moves even further up, and the block is ejected.

The machine can be operated by one person, although a more efficient operation would be achieved by a team of four or five people. Production is reported to be as high as 500 blocks a day with such a team.Using inserts in the press can allow one to transform the rectangular volume for specific purposes, i.e. holes for reinforcing, patterns for decoration, grooves for attaching other systems, a hollow interior to reduce material volume and weight. See the Links page for commercial vendors of cinva machines or a source for plans to make your own. (I made this one.)

The Cinva Ram in action at Mississippi State University. The image on the left shows Nathan Jeffreys and John Stantz putting the loose mix material in the Ram. The image on the right shows a block being ejected after the compression cycle.

I consider the pedagogical value of the work to be as follows:

• as a "learning-by-doing" educational vehicle, that has a value in general learning about building design and construction;
• as a way of making architecture students think about alternative construction systems;
• as a way of making architecture students think about issues confronting other building cultures;
• as a way of opening doors to understanding about masonry construction systems (of all kinds);
• as a way of introducing the idea of rigorous research methodologies to architecture students;
• lastly, as a way of building a limited knowledge base about stabilized earth block construction.

(For slides and video of a talk I gave on the pedagogy of the project at MIT in the summer of 2000, click here.)


The work at Mississippi State University consisted of having students in my Materials class (for sophomore undergraduates) experiment with different mix designs, then understand the consequences of each mix with respect to compressive strength, aesthetic issues, durability, density, etc.

The work at University of Kansas took place in a third-year undergraduate design studio, and consisted of background research into understanding desirable soil properties in locally available soils, understanding how stabilized earth works with respect to the natural forces at work on buildings in this climate, development of stabilized earth building assemblies, and the design of a building on the KU campus.

I have compiled a links page of sites pertaining to stabilized earth, alternative construction, etc.

One of the most valuable lessons to come out of this work (for both me and the students) is the value of collaboration. Accordingly, grateful acknowledgement is given to the following individuals, without whom this work would have not been possible:

First of all, to the students at Mississippi State University and the University of Kansas:

MSU students: John Stantz, Nathan Jeffreys, Jason Labutka, Stan Gray, Dan Nelson, Nhan Nguyen, Mike Dykes, Ban Kavalsky, Heather Edris, Shomari Lacy, Kyle Overstreet, Brad Heath, Jeff Elder, Charlie Watson, Robert Blue, Michael Mann, Melissa Nelson, Elena Poole, Leigh Ann Black, Kandi Soliz, Eric Vance, Jenny McGonagill, Brian Conner, Ismael Sheik-Hassan, Jeremy Taylor, Kristen Rowell, Lena Coleman, Tiffany Boyd, Jai Jang, Jeremy Spencer, Greg Durrell, Anderson Ervin, Patrick Smith, Kwayera Franklin, Heather Ray, David Maxwell, Sean Talley, Mike Brooks, Ryan Flynn, Brandon Bishop, Jason Pressgrove, Michael Boerner, Amy Catherine Cox, Jeff Seabold, Eric Whitfield, Jamie Weir.

KU Students: Melissa Brown, Enjoli Dixon, Nathan Freise, Aaron Harte, Jennifer Morris, Marshall Morrison, Micki Prinster, Angie Stutte, Tyler Robertson, Branden Warden, Chris Walla, Kristin Winters, Ashley Whitham.

Thanks is also due to the following individuals who have assisted us with this project:
Rusty McCulley and his staff at the Ag and Bio-Engineering shop at MSU, for help with construction of the Cinva-Ram;
George Mackie of Buildex (Ottawa, Kansas) for donation of Haydite (lightweight aggregate);
Dan Rockhill of KU School of Architecture and Urban Design for sharing his Cinva-Ram with us;
Dr. Bezaleel Benjamin of the KU School of Architecture and Urban Design for assisting us with structural issues;
Bill Morrison for donating the soil we used at KU;
Dr. Bob Parsons and of the KU Civil Engineering Department (and his graduate students) for helping us learn about soil testing;
Dr. Steve Cross
of the KU Civil Engineering Department helped us determine the compressive strength of some blocks.
David Boyer, Mike Dickie, Jason Netherton and Fran Gale of ProSoCo (Lawrence, Kansas) for helping us learn about masonry waterproofing and restoration.