PROBLEM STATEMENT: }

• There is a surplus of agricultural waste all around the world
• Third-World countries struggle to find accessible, affordable and efficient means of building.

PROJECT GOALS:

1. Compress natural waste material into a brick that could be used for building.

PROJECT EFFECTS:

DIVERGENT/CONVERGENT THOUGHT PROCESS:

Focus Area: Southern Mexico

Living Conditions

• 45.5% of Mexico’s population lives in poverty.
• Largest amount of poverty coming from Southern Mexico.
• Many of the poverty stricken areas are made up of small shanty towns.
• Lack of safe and affordable housing.

Site Constraints

Climate

• Moderate to Warm tropical temperatures
• Tropical storms are common
• Flooding can occur

Southern Mexico is seismically VERY ACTIVE. South Pacific coast is essentially the fault line between the Cocos plate and North American plate. Average magnitude of earthquakes in Southern Mexico are between 6.0

Local Building Materials

• Straw
• Henquen
  • The leaves of Agave fourcroydes yield a fiber also called henequen which is suitable for rope and twine, but not of as high a quality as sisal. It is the major plantation fiber agave of eastern Mexico, being grown extensively in Yucatán, Veracruz, and southern Tamaulipas.
• Plaster or Concrete

Material Constraints: Straw Bale

Advantages

• waste product
• affordable
• locally available
• low embodied energy
• biodegradable
• more flame retardant than conventional wood-frame construction
• highly insulating

Disadvantages

• Cannot be exposed to moisture
• Susceptible to insects and mold
• Some square footage is lost within the wall space
• If not stacked properly, can create thermal break-points
• Skin irritant (during construction)
• Plaster needs regular maintenance

haybale construction.png

Pro’s

• high insulating qualities (approximately R=42)
• high sound absorption coefficient
• simple, easy-to-learn construction techniques
• structure can utilize standard construction techniques
• inexpensive material that is usually available locally
• natural and completely biodegradable material
• renewable material, needing only a single growth season (with grain head harvested as cash crop)
• requires very little energy to produce
• diverts farming waste material
• aesthetics of a thick-walled building with large window sills

Con’s

• requires careful detailing to prevent liquid water infiltration
• requires breathable finishes, usually natural plasters, which may necessitate research or hiring a consultant
• necessitates educating yourself, the builder, and permitting officials
• requires more interaction with building officials in regions that do not currently have building codes for strawbale construction in place
• hired labor can be expensive, especially for plaster finishes

Capabilities

• Hold itself up, be self-supporting and resist tipping.
• Keep out the wind; inhibiting air/moisture infiltration.
• Resist heat transfer (insulation)
• Reduce water intrusion and migration, store and transfer moisture within the wall.
• Keep the assembly from buckling, under a compressive load.
• Keep the assembly from deflecting in a strong wind, when pushed from the sides or end.
• Keep the assembly from bursting apart in an earthquake, when pushed and pulled from all directions.
• Hold the plaster at least while it’s curing.
• Keep the plaster from cracking after it’s cured, from shrinkage or movement.
• Support the plaster skins from buckling.
• Transfer and absorb loads to and from the plaster.
• Support the roof load (compression).
• Reduce damage or failure from high winds (ductility).
• Reduce damage or failure from earthquakes (ductility).
• Stop bullets and/or flying debris.??

Types

1. Load-bearing straw bale walls — including the plaster interior and exterior wall coverings — support the roof and lateral loads (such as wind).
2. Non-load bearing straw bale walls typically consist of a post-and-beam structure, which supports the roof and lateral loads. This structure is in-filled with straw bales that provide only insulation.

Design Qualities

1. Load-bearing straw bale walls — including the plaster interior and exterior wall coverings — support the roof and lateral loads (such as wind).
2. Non-load bearing straw bale walls typically consist of a post-and-beam structure, which supports the roof and lateral loads. This structure is in-filled with straw bales that provide only insulation.

Cob Data:
The data is from the Guateca 2012 group that were testing out different materials and ratios for their cob.
The first image shows the different types of mixtures they used and the ease of making it.

The next two pictures show how each brick performed, looking at a specific detail in each.

With these results it seems that making a cob with a mixture of ratio of 1:1:1 (Clay:Sand:Fiber) tends to be the strongest while increasing the clay and reducing the fibers (2:1:0) it will make the cob look better with less cracks.

Group Members

Colton Baker
Mayra Concepcion
Jared Desbrow
Alejandro Lopez
Michael Pollack
Jonathan Allen

Making design plans! From left to right: Alejandro, Jared, Mayra, Colton, and Michael. (Jonathan not shown).

Good work, but could you update the website to show the finished product, and have a statement of how you finished the process? Additionally, could your correct your description to describe the process you actually did rather than what you originally planned on doing?

Past Correspondence:

Good Start, with information from location and technology. Did you add a person to your group? If so, please update the picture and contact information. Continue to build your website to tell the story of your project.

I noticed that you took data from the Guateca 2012 group. It’s worth noting that the structure that they built cracked pretty badly, so they should have used more sand and less clay in the mixture. Additionally all soils are different, so it is important to test your own mixtures on site.

What does “CMU” mean? Is that last document your “moderate fidelity prototype?” If so, please label it. It seems expertly done (The document itself might receive ~ “A”), but could use a title and explanation of what you’re going to do, and where. You could add links to the SEF page. Please state what you’re doing – this is a load-baring wall? Also, is this design (putting cob over the straw) your own design? I’d appreciate some direction with this regard and/or references as to where the ideas come from. Besides describing which design you are going with, please share the decision matrix that arrived at that design.