Abstract:
One of the basic human needs is having a proper shelter. Due to the rapid population and urbanization
growth, there is an escalating demand for affordable housing in Kenya. This necessitates looking for ways
to reduce construction costs, particularly for low-income housing group. Concrete-block construction has
recently gained significance, however most of the commercially-available block-making-machines are
imported and also expensive. Locally-made affordable block-making-machine would render useful in
lowering the cost of construction. This project, therefore, was aimed to complete a conceptual design of an
innovative undemanding stationary manually-operated concrete-block-machine that molds concrete-blocks
at a fraction of a cost in comparison with power-operated options. The target specifications were derived
from the customers’ needs data collected during the local workshops’ visits and from the secondary sources,
mainly patents. Three design alternatives were developed; alternative design #3 was chosen by the
engineering design decision-weighted-matrix and by the drop and re-vote (D&R) method. The originality
of this design is essentially in the ejection system: as opposed to many block-making-machines available
which ejects blocks instead of the mould, this machine ejects the mould leaving the blocks on the base
plate. Mild steel was a material of choice for the machine. A static simulation study on the frame model,
which was fixed at the bottom mounting and an overall normal force of 981N or 100 Kg applied at the base
plate was done using Engineering Design Software: SolidWorks, 2013 (design and simulation tool). The
study included Stress, Displacement, and Strain analysis. Conceptual design of manual-concrete block-
making-machine was optimized according to results of simulations, calculations and fundamental
engineering design principles. Cost estimation shows that this simple and economical piece of equipment
could have a potential in lowering the cost of construction. To ascertain a potential, however, the authors
propose further work on prototyping and testing to be carried out.
