dc.description.abstract |
Present concerns for sustainable development have led to a revival of traditional
building practices using natural or recycled resources. There is a perception that
the use of earth as a conventional construction material is likely to save
manufacturing and transportation cost, time, energy and environmental pollution.
Stabilized compressed earth block is an innovative advancement of the traditional
earth technology that involves adding a little quantity of stabilizer such as cement
to earth and making compressed earth blocks. While available research has
focused on performance of typical soils, no research has delved into the structural
performance of the several types of soil available in Kenya. Moreover, no research
has sought alternative and cheap stabilizers for these soils.
In this research, three types of soils available in Kenya (murram, red coffee and
black cotton soils) were used. Different percentages of stabilizers such as cow
dung, quarry dust, waste paper, plastic fibre, cement and limes were also used. In
order to evaluate the different kinds of stabilized earth as sustainable and
acceptable construction materials for eco-housing construction in the African subcontinent,
this experimental work delved into basic material properties, as well as
strength tests on specimens made of blended or composite soils. Tests conducted
include Atteberg limit, particle density, particle size distribution, compaction and
linear shrinkage test on different soils as well as strength test on composite blocks
and walling unit. The percentages of stabilizers used were 4% and 6% for cement,
4%for lime while the soils were blended with sand and quarry dust at varying
percentage. Further, this study also involved blending the soil with cow dung,
waste paper and plastic polythene fibre at varying ratios as well as alternative
compaction method.
Result obtained from this study show that murram blocks stabilized with 6% of
cement had a satisfactorily higher strength of 4.4MPa which is above the
minimum strength required by Kenya standard of 2.5MPa. When an alternative
compaction method involving both hand compaction followed by machine
compaction was used, the compressive strength of blocksat 28 days increased
from 3MPa to 4.3 MPa, from 3.9MPa to 5.2MPa, from 4.4MPa to 6.2MPa for
composite black cotton soil, red coffee soil and murram soil respectively. The
results obtained further reveal that stabilized black cotton soil blocks blended with
20% cow dung gave a strength of 2Mpa, which is much higher than the strength of
unblended black cotton block of 0.6MPa. Furthermore, the results of compressive
test on wall panels show that the compressive strength of stabilized compressed
earth block wall is higher than the compressive strength of stone blocks wall. It
also showed that 40% of the cost of construction materials could be saved when
stabilized compressed earth blocks are used as alternative construction materials. |
en_US |
dc.description.sponsorship |
WALTER OYAWA (Department of Civil Engineering, Jomo Kenyatta University
of Agriculture and Technology: JKUAT, Kenya)
TIMOTHY NYOMBOI (Department of Structural Engineering, Moi University,
Eldoret, Kenya |
en_US |