TESTING OF SOIL FOR BRICKMAKING
- Get a handful of soil and add enough water to make it sticky.
- Mold it into balls and dry under the sun for 2 to 4 days.
- See whether the dried soil cracked or not. If it remains firm and hard the soil is clay.
- Test another one with this procedure.
Conduct another test by molding 4″ x 10″ x 2″ and burn with rice husk for one week. Good clay when dried by this method will sound metallic when tapped.
There are three (3) types of manufacturing methods for bricks:
- Soft-mud with repressing machine
- Mechanical method
Methods 1 and 2 are most suited for cottage industry. They are manually generated and require only a small capital.
Method 3 used machines for raw material processing and farming. Even if most of the machine can be made it still needs a big capital investment.
1. Raw clay is left in the open for stock piling with a duration of about two (2) months or until the clay disintegrates thru the action of sun and rain.
2. The disintegrated clay is brought to the processing area. Sandy clay, plastic clay and sand are mixed in their proper proportions. Water is added to combine clay mixture.
3. Knead either by hand or foot for about three (3) hours.
4. After kneading, the clay should be aged for two (2) days to get a homogeneous mixture. Aging distributes its workability and lessening the possibility of cracking during drying and firing.
5. Form the clay into a wooden mold.
6. The formed bricks from the mold are then placed on a pallet and allowed to dry to leather hardness for not more than two (2) days.
7. The leather hard bricks are retouched to remove the finger marks and scratches due to forming and handling. The retouching work can either be done by skillful hand manipulation or by machine for better and faster finishing.
8. Retouched bricks are kept in the drying area until they are completely and uniformly dried. The drying takes about two (2) weeks during dry season and four (4) weeks on a rainy season.
9. When dried, put the clay in improvised kiln. Arrange them loosely and pour rice hulls in between the spaces.
10. Set fire from the bottom. Baking process takes one week.
Materials: clay, sand, water
Tools: shovel, hoe, pickax, strainer, wire #14, wooden scraper, wooden molds 10″ x5″ x12Â½”, gas oven
- Dig soil, remove stones and waste with the use of strainer.
- Mix with:
- 25% water (1 part water in 4 parts of soil)
- 10% sand (10 parts of sand in 10 parts of clay)
- Mix well.
- Put in molds, scrape excess.
- Remove molds and let dry bricks within 3 to 4 weeks at room temperature.
- Invert brick so it would not crack or form wrinkles.
- Preheat gas oven for 2 hours at 980Â°C.
- Arrange bricks alternately
- Bake for 16 hours.
- Cool before use.
Due to the increasing cost of cement, the Forest Products and Industries Development Commission (FORPRIDECOM) conducted a research that will produce blocks from soil and water, or a combination of one or two different wastes or wood waste like rice hull, coconut coirdust or sawdust. The binder used is lime. Lime can be found almost anywhere in the Philippines.
- lime rice hull
- coconut coirdust rice hull ash
- sand wood ash
- 1/4″ wire screen
- Powder the soil and remove lumps by using 1/4″ wire mesh screen.
- Mix well any combination of one or two of the following:
- a. 3 parts soil + 1 part coconut coirdust
- b. 3 parts soil + 1 part rice hull
- c. 5 parts soil + 1 part lime
- d. 5 parts soil + Â½ part lime + Â½ part rice hull ash
- e. 5 parts soil + Â½ lime + Â½ part wood ash
- f. 4 parts soil + 1 part rice hull + 1 part lime
- g. 2Â½ parts soil + 2Â½ part sand + Â½ part lime + Â½ part wood ash
- Make a mountain-like of any of the combination and put a well at the center for water.
- Pour the material combination on the well slowly and mix with shovel. The result must not be too dry or too wet for moulding.
- Place in molds. Shake and scrape the top.
- Dry under the shade for a few days.
- Dry under the sun for few days.
For more information, contact:
Dept. of Science and Technology
Rm. 303 DOST Bldg., DOST Complex,
Gen. Santos Ave., Bicutan, Taguig City 1631
Telephone Nos: (632) 837-20-71 to 82
Fax: (632) 837-8937
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