Abstract:
Need to develop affordable housing is necessary because of the numerous homeless
people living in the developing countries; the present work is an attempt to alleviate the
housing problem facing populations of these countries. In the current investigations, a study programme illustrating the effect of various sisal,
cement, cement-sisal and cassava proportions to the compressive strength, flexural
strength, dry block density and porosity of compressed earth blocks (CEB) is outlined.
A constant volume manual press has been used to fabricate earth blocks, at a fairly
uniform pressure. The relationship of strength, block densities and porosity to
reinforcement levels has been determined. A considerable increase in strength with increasing sisal fibres, cassava powder,
cement as well as cement-fibre content within certain limits is observed. Results show
that sisal fibre content outside these stated limits are detrimental to the strength
characteristics of compressed soil blocks. The critical sisal fibre volume for soil-sisal
mix has been established. Compression and flexural strength at optimal fibre content
are comparable to those of soil blocks stabilized by the already well studied
conventional binders as cement; besides, these results are not recorded in literature
yet. Dry block densities and porosity reflect closely on the fibre, cement, cement-fibre
and cassava content. Light optical microscopy (LOM) and scanning electron
microscopy (SEM) analysis have been used to verify the block morphology. Compressed earth blocks manufactured from a limited addition of cassava powder to
the soil, show improved strength. Indeed the ideal strength is above one recommended
by various CEB standards. Past researchers have not documented any research
related to cassava as a building material. Water vapour transmission properties of the
earth blocks have been determined; values show that the earth blocks may provide
better indoor air quality than conventional building materials like concrete. A simple
method by which strength of earth blocks could be determined in the absence of
laboratory facilities in the rural villages of Kenya and related regions has also been
developed
