Abstract:
—This research reports on the investigation into the
strength and durability in-terms of shrinkage of compressed
earth blocks produced from natural site soil and modified or
reconditioned soil types.
The soils were stabilized chemically by cement and lime
stabilizers with a mix proportion of 5 and 7% cement as well as
10 and 15% lime, the control treatment being with no stabilizer
(un-stabilized) in both soil types. Hence, for each soil type five
different treatments were considered for the study. Four blocks
were produced for each treatment.
The engineering characteristics and classification of soil samples
were determined by applying suitable tests. Furthermore, the
compressive strength, dry block density and dimensional
stability in-terms shrinkage (volume change) of the sample earth
blocks were investigated after the elapse of their respective
curing periods.
In general, significant improvements in dry compressive
strength and dimensional stability characteristics were exhibited
by the stabilized and compressed earth blocks. With regard to
dry compressive strength of blocks, the result showed that the
average compressive strength of cement stabilized blocks were
found to be 1.42 and 1.53MPa in case of natural site soil and
2.73 and 2.90MPa in case of the modified soil with a mix
proportion of 5 and 7% of cement by weight respectively.
Similarly, the average compressive strength of lime stabilized
blocks were found to be 1.45 and 2.20MPa in case of natural
site soil and 1.38 and 1.45MPa in case of modified soil with a mix
proportion of 10 and 15% of lime by weight respectively.
Accordingly, by considering a minimum dry compressive
strength of 2MPa as an acceptable strength, the 15% lime
stabilized earth blocks in the case of natural site soil as well as
the 5 and 7% cement stabilized compressed earth blocks in the
case of modified soil have shown a dry compressive strength
value greater than 2MPa and hence can be conveniently used as
an alternative durable and affordable wall building elements in
Jimma area.
