Abstract:
The conventional method of bricks production using clay soil has brought natural resource
depletion. In Jimma City and around Jimma there are high amount of Spent coffee ground and
Plastic Waste thrown everywhere in the city. The aim of the study was to investigate the
suitability of the mixture of clay soil, spent coffee ground and plastic waste for production of
bricks. The specific objective of the study were evaluating index properties of clay soil and
general properties of poly ethylene terephthalate and spent coffee ground, examine the physical
and mechanical properties of the produced bricks, determine adequate firing temperature of
produced bricks and determine the optimum percentage replacement of coffee ground and
plastic waste as brick raw materials.
According to this research methodology, control bricks and four other different percentages of
spent coffee ground and plastic waste with clay soil were replaced 2, 4, 6 and 8% and 1.5, 3, 4.5
and 6% by weight respectively manufactured. The laboratory test result of mean compressive
strength for this study, the 2, 4, 6 and 8% spent coffee ground and 1.5, 3, 4.5 and 6% plastic
waste and control bricks at 8000C firing temperature were 16.51, 20.62, 14.42, 13.52 and
23.43Mpa respectively. The maximum compressive strength was at 3% Plastic Waste and 4%
Spent Coffee Ground replacement fired at 600, 700, 800, 900 and 10000C which were 13.72,
16.31, 20.62, 16.72 and 16.37MPa respectively. The produced Bricks were fulfills Ethiopia
standard and America society for testing and materials standard.
Based on the 8000C firing temperature, Water absorption for all percentage replacement and
control bricks were 21.44, 21.62, 22.15, 22.35 and 20% respectively. The efflorescence test
results show that, all of the produced Bricks were not effloresced and the dimension tolerance
test result was satisfied for construction purpose as Ethiopia standard and America society for
testing and materials standard.
Finally incorporated spent coffee ground and plastic waste with clay bricks were better for
construction purpose by fulfilling the standard in addition to giving safety for environment and
natural resource depletion. Therefore, the concerned government bodies, society, Small and
micro enterprises and the user shall adopt the mixing spent coffee ground and plastic waste with
clay for brick production.
