Browsing by Author "Udawattha, CD"

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item: Thesis-Full-text
The Effectiveness of alternative stabilizer for mud concrete technology
Udawattha, CD; Halwatura, R
The building wall is our third skin. Edifice the third skin out of earth has been practiced since prehistoric era, because of the availability of soil as a raw material. Merely soil have many weakness including its geo technical properties of shrink swell, low density and high permeability. In order to convert geotechnical properties into engineering material, there should be a stabilizer. This study was conducted to study alternative stabilizer for earth based construction particular to mud concrete earth construction. An inventory of potential alternative stabilizers were arose based on an immense literature survey, inspired from nature and from ancestral folk knowledge. Several mix designs were subjected to a strength development study. Overall engineering properties and total life cycle study was conducted according to engineering standards. The durability, cost, thermal performances, embodied energy and life-cycle cost were studied and compared with most available wall construction units. Finally, the impertinent technology was enhanced to use as residential scale technology for poor people in the country. The application and the manufacturing process was advocated among low income villagers to building their houses. The study has found that natural polymers such as natural rubber latex, pines resin, dawul kurudu, and sugarcane bagasse can enhance the mechanical properties of a mud concrete block. Industrial waste such as fly ash, bottom ash, and rice husk ash can work as an alternative stabilizer. A more advanced technology of geopolymerizing mud concrete block was invented by this study. In the practical construction world, this novel wall material should be testified in front exiting wall material palette. Found that mud concrete block is a suitable solution to replace existing expensive wall construction technology. Finally, the manufacturing process was optimized into the plenteous production process to manufacture mud concrete block in mass scale. More than all, this thesis has given birth to an affordable wall construction technology for poor people in the country.
item: Conference-Full-text
Fly ash-based geopolymer mud concrete block
(IEEE, 2018-05) Udawattha, CD; Lakmini, AVRD; Halwatura, RU; Chathuranga, D
The high production of fly ash due to the combustion of coal causes several environmental problems such as water pollution, air pollution, etc. Therefore, the use of fly ash as a stabilizer for the construction of mud concrete will reduce these problems. The idea of building mud concrete blocks is to convert stable natural soil into an engineered block. Mixing fly ash alone did not generate a significant strength. For a loaded construction, the minimum dry compressive strength must be greater than 2N/mm2 and the wet compressive strength must be greater than 1N/mm2. This investigation is carried out to evaluate the alkaline activation of the fly ash to stabilize the soil and build geopolymer self-compacting mud concrete blocks. Alkaline activation of fly ash to build geopolymer is not a novel concept. But employing the idea in self-compacting mud concrete is new study. Initially, it was found that the optimum content of fly ash stabilized the soil. It was found that NaOH and NaCl can increase the pH content of the mixture and increase the resistance to the required level. Ultimately, heating can develop a much better mix than cement stabilized mud concrete mix.
item: Conference-Full-text
A study on natural rain surface erosion of different walling materials in tropics
(IEEE, 2018-05) Udawattha, CD; Galkanda, GAHH; Halwatura, RU; Chathuranga, D
This study presents most common phenomena observed on wall facades due to excessive rain in tropical climatic condition in Sri Lanka. The objective of this study is to understand the effect surface decay of walling materials. The most common walling materials such as brick, cement block, earth cement blocks and novel walling materials mud concrete block, geopolymer blocks were subjected to this study. Faade covering materials such as rough cement plaster and cement slurry plaster were studied. Intrinsic material properties were studied prior to natural rain erosion quantification. Basic engineering properties of water absorption, capillary action, surface roughness, compressive strength was studied. Material properties such as water absorption, surface roughness were studied. Ten years of rain was simulated to measure natural surface decay. The results show that, stronger materials and less surface rough materials are resistant to surface decay. Plastering is recommended to protect walling materials reduce the surface decay. Comparatively stronger walling materials are less prone to natural rain decay. Cement plasters and cement slurry plaster covering is the most suitable materials for heavy rain. Cement slurry plaster is the most suitable walling covering for rain drop bouncing areas in outdoor walls in Sri Lanka.