| dc.description.abstract | Bricks are oldest building materials since 7000BC, and are preferred as building
material due to their high compressive strength, fire & weather resistance, thermal &
sound insulation and durability. l11e artisan clay bricks in Uganda are characterised
with low strength, erosion, tiny cracks, lime pop out, warping, efflorescence and
high-water absorption. The raw clay and artisan burnt clay brick samples were
collected from artisan brick making places (sites) from Eastern, Central and
orthcrn Uganda. The sampling was done using JS-5454 procedures. Testing was
carried out for water absorption, mineral percentage investigation in natural and
purified clay in terms of sio2, Ah03, Fe203 & CaO, compressive strength of the
artisan clay unit, improved chemical composition artisan clay units from purified
clay and improved molded bricks from raw clay. Results indicated that mineral
requirements for manufacturing bricks was not satisfactory; for artisan bricks, they
had very low characteristic strengths of 0.63N/mm2 for Lira and 0.38N/mm2 for
Mukono samples. Refining and change on molding process was done and the raw
clay structure shifted to the positive side of the required mineralogy. Fired bricks on
testing gave higher characteristic strengths of 2.2 N/mm2 after purifying and
3.3N/mm2 after use of improved mold for Lira, 5.12 and 2.62N/mm2 respectively for
Mukono, slight efflorescence and low water absorption. This study therefore
recommend that the artisan do include both clay refining processing and constant
force kneaded clay pressing in the manufacturing process.
Key words: Strength, brick structure, chemical stability and durability in Uganda | en_US |
