The higher the clay content, the more orange the dirt appears.
A science project examining brick making is most suited for a high school student, although it could be completed by a committed middle school student who is interesting in construction and is not afraid to get dirty. Handmade brick from natural clay deposits consist of clay, sand and dirt in various proportions. By testing those proportions, the student can determine where or how the strongest bricks can be made.
Research
Before beginning your science project, research methods of making clay bricks by hand. Focus particularly on the proportions of sand, soil and clay in bricks. The rule of thumb in brick making is that bricks with higher sand-to-clay ratio are stronger. Talk to masons in your area. Research the Internet for persons or companies that still make clay bricks by hand who can impart practical knowledge. Contact the Soil Conservation Service or the U.S. Geological Survey to locate areas of clay-bearing soil in your state and the recorded proportions of clay to sand.
The Experiment
Based on geological data gathered prior to beginning your experiment, choose three to five areas to test the ability of the soil to make quality bricks. Rank these locations highest to lowest according to the proportion of sand to clay and hypothesize which location will make the strongest bricks. Alternatively, you can choose a single location of high clay concentration and add different amounts of sand to the soil that you harvest and predict which bricks will be the strongest.
Testing the Ground
While the U.S. Geological Survey will have used sophisticated scientific equipment to verify the exact proportions of sand, soil and clay in the area you have chosen to harvest for brick making, you can field-test the soil to determine an approximate proportion. Add 3 inches of dirt to an 8-ounce glass jar with lid and fill the jar with water. Shake the jar vigorously to suspend the dirt in the water. Allow the jar to sit overnight. The clay will precipitate out the water more slowly than the sand and soil, producing a clearly defined line between the two components. Use a ruler to measure the height of each division and divide it by 3 inches to get the percentage of each component in the soil.
Testing Your Brick
Make at least five bricks from each soil location that you test or each proportion of sand that you add. Allow the bricks to dry for a minimum of three weeks. You should try to make all of the bricks on the same day or within two to three days to guarantee that drying time does not factor into the strength of the bricks. Roll each brick end over end five times and record the results. Next, stack 50 pounds of weight on each brick and wait five minutes. Finally, immerse each brick in water for 30 seconds, then remove the brick. If the brick breaks, cracks or disintegrates during any of these tests, you do not need to continue testing in the next step. The batch of bricks containing the highest number of individual bricks to pass all three tests should be declared the strongest.
Tags: sand soil, brick making, clay bricks, each brick, beginning your, bricks hand
