Available at: http://digitalcommons.calpoly.edu/theses/176
Date of Award
MS in Architecture
Craig Baltimore, James Mwangi, Kevin Dong
ANALYSIS OF STABILIZED ADOBE IN RURAL EAST AFRICA
Grace Ying Yu Chen
This project seeks to assist people in rural East Africa by proposing sustainable building methods which implement affordable and durable adobe bricks for construction. Adobe, one of the oldest sustainable building materials in the world, is strong when dry but lacks structural integrity when exposed to moisture. Chemical additives such as cement and lime are added into the adobe mix to protect the brick against moisture decomposition. Once the chemicals are added and the mix is formed into a brick, a stabilized adobe brick is formed.
Cement, a stabilizer, is locally available in East Africa, but is generally unaffordable for families in rural areas. Lime is also locally available and costs about half the price of cement. This project investigates reducing the amount of cement to produce an economical and stabilized brick. The tested brick mixes, measured by volume, were
• 10% cement
• 5% cement
• 5% cement+5% lime
• 7% lime with sand
• 7% lime with clay only
• 10% lime with sand
After testing these bricks by water jet, submersion, modulus of rupture, and compression, the 5% cement+5% lime mix and the 7% lime with clay mix proved to be viable options for economical and durable bricks.
The second half of this project contains summaries of research related to stabilized adobe and other soil building methods. A literature search shows that lime mixed with soil containing small particles rich in calcium carbonate and quartz produces proper cementation in the mix called carbonation.