Browsing by Author "Sanjeewa, KWD"

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    item: Conference-Full-text
    Performance evaluation of emulsion/water-gel explosives and comparison with dynamite in Sri Lankan quarrying practices
    (Department of Earth Resources Engineering, 2011-11) Sanjeewa, KWD; Fernando, PLD; Zoysa, AUD; Ramees, AM; Hemalal, PVA; Dharmaratne, PGR; Ratnayake, NP; Amarasinghe, AMKB
    At present, Dynamite is currently manufactured only in a few countries as a commercial explosive due to its high cost hazardousness. Therefore import and supply do not match the demand patterns which inevitably result in considerable inconvenience to the quarry industrialists to certain degree affecting the development of this industry which has a direct bearing on the country's infrastructure development. Consequently, there is great necessity to manufacture high quality explosive of low cost and less hazardousness as a substitute for Dynamite. By using Magnesium/micro glass bubbles/ Aluminium, instead of the main sensitizer (Nitro Glycerin) of Dynamite, Slurry explosives (Water-Gel) are manufactured under the similar process as a powerful explosive. In this instance, the industrialists have been compelled to use the low cost but almost untested explosive as a substitute. Research so far carried out only show that the product is substandard which dictates further the investigation.
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    item: Thesis-Full-text
    Utilization of building debris as aggregates in stone column construction in Sri Lanka
    Sanjeewa, KWD; Nawagamuwa, UP
    Due to rapid development and population growth, construction industry has emerged with few recent problems. The major problem faced by the construction industry is the scarcity of construction material and disposal of construction waste because of high disposal cost and inadequate land fill area. Due to the remnants of 30 year civil war happened in Sri Lanka, huge amount of building debris are to be disposed during new infrastructure constructions. To curtail the amount of building debris, the possibility of using them (concrete, brick and plaster) for civil engineering applications can provide an attractive way to reduce the wastes to be disposed of and it may also provide fiscal benefits. In this study, the scope for using building debris as the traditional rock aggregate for stone columns was investigated. Experiments were conducted using building debris(concrete, brick and plaster)and stone aggregate passing through a 14 mm and retained on a 10mm British standard (BS) sieves. Where experimental studies were carried out to determine the engineering properties (Durability, Shear strength & Compressive strength) of the recycled construction material and compared with conventional road construction material (aggregates). AIV, ACV and LAAV tests and slake durability index test were carried on selected building debris to find out the suitability to be used in stone columns construction.And uniaxial compressive strength testwas carried out to find the resistance to impact and crushing under loads. Improvement in shear strength was tested using vane shear in radially as well as with depth in several laboratory models with a centred stone column made up of different building debris. It was observed that the model done using concrete wastes exhibited a similar capacity of traditional rock aggregates of same size. Other materials did exhibit the same behavior though their results from slake durability tests were relatively low.