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.
See Full PDF See Full PDFInternational Journal of Engineering Research and Technology (IJERT)
https://www.ijert.org/design-analysis-and-development-of-improved-hollow-concrete-block-making-machine https://www.ijert.org/research/design-analysis-and-development-of-improved-hollow-concrete-block-making-machine-IJERTV9IS030329.pdf This project report deals with the design and development of an improved hollow concrete block making machine. The machine lays a particular number of blocks over the platform and moves further to lay another set of blocks, so as to cover the casting platform, in a continuous casting process. This study attempts to solve the problems encountered on the existing hollow concrete block making machine by improving the design of basic components, increasing production rate and minimizing damages of uncured blocks during transfer. The design is based on data from literature review about Concrete in building construction, Concrete block machine developmental stage, how concrete block making machine works and manual calculation. To meet the objective based on the design principles several component mechanisms are improved and analytical design analysis, part drawings and assembling drawing are also done.
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This paper reports the synopsis of design simulation and analysis of manual block-making machine; it is a small fraction of a bigger research-study. Analysis of the various components that make up the final design was done in order to establish the forces, stresses and dimensions. The studies included dynamic simulation, frame analysis and stress examination. Finite Element Analysis was conducted on the components that could have failed during the normal operation of the machine; as such two analyses were done, one to investigate the effect of member components weight due to gravity and the second to investigate the effect of the return load on the frame members. All drawings, calculations, design, assembly, simulations, and Finite Element Analysis (FEA) were done by the Autodesk Inventor, 2016 Engineering Design Software. The results are: Flat lever analysis: The maximum displacement achieved was 0.0000008642mm, while the safety factor was 15ul and so the design of the flat component was acceptable if subjected to loads as exposed. However, it seems that the part is overdesigned. Compactor frame analysis: The maximum displacement was 1.605mm and considering the fixed-end would not actually be fixed in the actual machine, this displacement was found to be acceptable. The minimum safety factor achieved was 4.35ul which is acceptable and the maximum 15 ul. Complete assembly analysis: Maximum contact pressure achieved was 36.72 MPa while some components received no contact pressure from the load. The safety factor for the whole machine was 15ul. The value may lead to an assumption that the machine has been " overdesigned " , but considering that some of the sections of the machine are actually unaffected by the load, or the loading conditions is short, and allowing for that it is an equipment that intends to operate on a daily-basis, and it is made of ductile-material, operated in repeated and impact mode of loading, environmental considerations and also to account for all the unpredictable-factors, then, this safety factor for the machine is acceptable. For single components however there would be a need to reduce the " overdesigning ". The study accomplished design simulation and analysis of manual block-making machine, resulting in 3D-view of the final assembly of the machine (made of mild steel) with all standard notations. Overall, the results of this concise study are rather positive, providing a good starting point for further and much-deeper exploration on the same. The major recommendation was made vis-à-vis design factor of safety, in order to eliminate/reduce " overdesigning " and to obtain sequential solutions that exhibit asymptotic convergence to values representing the exact solution, it is recommended to conduct h-refinement of the mesh in FEA.
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JOurnal of Engineering and Applied Sciences
The design and construction of a twin-block making machine was carried out as an improvement on the manual production of single block locally with a lot of ergonomic problems resulting from frontal loading and back straining. Material mix is fed into the machine, compressed and cranked up to remove the blocks from the mould. The machine is powered manually by a chain operated lever arm. The machine is capable of producing two standard size blocks, (457.2x127x228.6) mm3 and (457.2x152x4x228.6) mm3 per operation . The calculated work (input) required to lift the two-block load of 529.5N through a height of 0.279m by the machine has been determined to be 147.73J with an effort arm of 99.15N . The output of the machine in terms of production capacity indicated that the machine has a throughput of 800 blocks/hr compare to hand mould with 432 blocks/hr, one moulder/operator and a helper. The efficiency of the machine was found to be 92.4%.
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