Other Research – Reports

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Alternative building materials for Sri Lanka
Jayasinghe, C
The housing requirements in Sri Lanka is rising due to growth of population and urbanisation. Due to change in socio-economic conditions and the living patterns of the society, there is a tendency for every individual family to own a house. Persons of middle income and low income groups have only limited funds at disposal for house construction. Majority of the population raise the funds required for house construction through bank loans, generally at around 15% to 20% interest rates with a payback period varying between 10 to 20 years. Since the amount of money made available is generally limited to ensure monthly instalments are within 40 % of the income the maximum amount that can be raised for house constructions also limited. This calls for construction techniques that achieve an utmost economy in house construction to suit the income of average and low income wage earners. The cost of housing in Sri Lanka has risen astromically in the recent past due to many factors, one of which is the shortage of building material to meet the demand of the building industry. One example is shortage of sand due to excessive sand mining. Another is land for clay mining to produce bricks. A direct consequence of the shortage of materials is the cost of building materials. This therefore calls for an urgent investigation in to the possibility of using locally available alternative building materials which can be used to replace the conventional building materials.
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Application of management frameworks for coastal zone management
Hettiarachchi, SSL
Sri Lanka is an island state with a coastline of approximately 1600 km and a land area of around 64,000 sq. km. Coastal erosion has been identified as a major natural hazard faced by Sri Lanka for a very long time. Its impact has increased at alarming rates due to unplanned human intervention in the coastal zone and with more than half of the country's total population settled in coastal areas, the unplanned development of coastal infrastructure resulting from increased settlements has naturally led to accelerated degradation of the coastal environment. Although the coastal problems of Sri Lanka have been recognized from the turn of the century it is in the last two decades that growing attention has been focused on these problems because they have been seriously aggravated
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Application of membrane separation processes to the Sri Lankan Industry
Amarasinghe, BMWPK; De Silva, IMBM
Membrane separation is a relatively new technology applicable for a range of separations. The technique is attractive due to its ability to produce high quality products, suitability for processing heat sensitive materials and possibility of recovering and recycling of valuables from waste streams. Current applications of membrane separations for liquid systems in the Sri Lankan industry and possibilities for future developments were investigated. The survey shows that only 5% of the industries considered for the survey currently use membrane separations. However, 51% have the possibility of using membrane separations either for water treatment, wastewater treatment or for separations in the manufacturing processes. Normal Filtration and Ion Exchange are the widely used techniques for water treatment. Reverse Osmosis and/or Ultra Filtration can be used for purification of water for medical and pharmaceutical applications, for preparing drinking water and boiler feed water from high salinity water or seawater. Pulp and paper, Textile and Diary industries have the possibilities of using MS for wastewater treatment and recovery and recycle of valuables. However, novel techniques such as PV can be used for removal of tracers of hazardous components. Further, Pervaporation, Osmotic Distillation etc. can be experimented for the manufacture of new range of products in food and biotechnological fields and for obtaining highly purified products. Despite the relatively high capital and maintenance cost and the problems of concentration polarisation and membrane fouling application of the technique for many Sri Lankan industries will be important in anticipation of future demands of high standards and minimal environmental impact.
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An appropriate method of production of rubberrised bitumen for road surfacing
Subramaniam, K; Thiruchelvam, AT; Raveendran, K
A laboratory scale method comprising two stages has been developed to produce rubberised bitumen based upon natural rubber. In the first stage of the method, natural rubber in the form of field latex, stabilised previously with ammonia and potassium hydroxide, was added in required proportion into 80/100 grade bitumen melt at 95°C, to give about 3% rubber in bitumen by mass. To facilitate the addition, the contents were continuously stirred by means of a multi-stage impulse counter current impeller (pitched paddle stirrer). In the second stage, the resulting temperature of the mix ' was gradually raised to 100°C. to vapourise the water content in the latex. The problems encountered during the vaporisation of water such as frothing, and rise in viscosity of the mix were overcome by altering the speed of the stirrer unit appropriately. The bitumen-rubber blend thus obtained, on testing for its quality, exhibits bettei technical properties than 80/100 grade bitumen for application in road surfacing
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An Assessment of off-grid micro hydro potential in Sri Lanka
Fernando, S; Senarath, R; Ananda, R; Sarath, DB
Viability of using off-grid micro hydro technology for rural electrification was first demonstrated by the Intermediate Technology Development Group (ITDG) in 1991. Following the demonstration phase, ITDG carried out numerous activities to create the enabling conditions for replication of this technology on a wider scale. The technology has gained popularity in Sri Lanka and its application is steadily growing.
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Building envelope performance index for commercial bl ilding energy conservation
Jayasuriya, JPW; Attalage, RA
The role of thermo-physical and geometrical characteristics of a building envelope that plays in the air-conditioning load of the commercial sector is highlighted. A standard methodology of quantifying a performance index for the building envelope is reviewed and upgraded orporating local climatic, material and architectural features. The methodology which is a trade-off between prescriptive and performance criteria can be easily used to form a basis for efficiency building code (EEBC) for Sri Lanka. The methodology is illustrated through a case study
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Building envelope performance index for commercial building energy conservation
Jayasuriya, JPW; Attalage, R.A.
The role of thermo-physical and geometrical characteristics of a building envelope that plays in the air-conditioning load of the commercial sector is highlighted. A standard methodology of quantifying a performance index for the building envelope is reviewed and upgraded incorporating local climatic, material and architectural features. The methodology which is a trade-off between prescriptive and performance criteria can be easily used to form a basis for an energy efficiency building code (EEBC) for Sri Lanka. The methodology is illustrated through a case study.
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Capacity building towards sustainability: context of post disaster waster management
Karunasena, G
Concept of Capacity Building is an essential component in development theory and practice. In developing countries, it is identified as a key concept in achieving sustainability. In particular, in post disaster scenarios, focus has been placed upon local capacity building as a means of increasing resilience to natural hazards. In this context, this paper focuses on concept of capacity building and its role on achieving sustainable post disaster waste management. A literature review and pilot study have been conducted to gather information on post disaster waste management in Sri Lanka. Semi-structured interviews were held as the main data collection method and content analysis was used to analyse collected data. Unavailability of a centralized body, poor implementation of rules and regulations; lack of skills and confidence, inadequate funds, lack of communication and coordination were identified as prevailing capacity gaps in post disaster waste management. Thus, finally paper proposes a framework for capacity building for sustainable post disaster waste management.
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A Case study on economic valuation of environmental services provided by the Bolgoda Lake Sri Lanka Phase I
Bhuvendralingam, S; Chanmugam, S; Wadugodapitiya, WO; Gunaruwan, TL; Jayawardena, K; Kotagama, HB; Sivagnanasothy, V
In the recent past, several countries in Asia have demonstrated robust economic growth, largely led by industrialization. A consequence has been rapid urbanization. About 30 percent (800 million people) of the total population in Asia, live in urban areas (cities and towns). This demographic shift towards a larger urban population is accelerating. It is expected that by year 2025, about 60 percent of the Asian population (2.5 billion people) will be living in urban areas. The number of large urban cities is growing rapidly in the region. Currently, there are nine megacities (those with the population of the more than 8 million) in Asia, and their number is expected to increase to 13 by the year 2000. The concentration of industrial activities and large populations in Asian cities have caused environmental problems with serious consequences that undermine the gains from growth to human welfare. Awareness to consider environmental conservation as an essential goal of development is increasing. Governments, the private sector, community groups are responding with a variety of initiatives such as investment on environmental management, controls on investments having potential to pollute the environment, encouraging the use of environment friendly technology, and creating awareness among population on need for urban environmental conservation. The physical magnitude of urban environmental degradation has been reasonably analyzed and understood. The economic impact of environmental degradation, however, has not been adequately analyzed, degradation has not been considered for rational policy-making. This leads to anomalies in prioritization of investments and selection of environmental management strategies and policies to economically efficiently mitigate environmental degradation
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A Concept of weather window (WW) in managing the rain risks in construction projects of Sri Lanka
Wiratunga, IVH; De Silva, N
Different weather conditions such as rain, wind and snow would directly impact on. , th, e performance of any construction project. Being a tropical country, the effect from rain wou I be experienced mostly in Sri Lanka. Within this context, risks caused from rain can be defined in financial terms as a loss or gain due to a change in weather conditions over a period of time. Weather records available in the Meteorological Department of previous years are analysed to establish the different rain risk categories based on dry spell, rain spell, and wet spell which are derived from a “wet day ” as defined by the Meteorological Department. In this research, the value used to define the wet day is modified to establish the "weather windows (WWs),” under above rain risk categories, namely as major weather window, moderate weather window and minor weather window. These established WWs are applied to a completed project and analyzed at different risk conditions. It was identified that the concept could be used effectively to manage the rain risks. The results showed that 3.5% of the total project cost would have been saved, if the weather sensitive items such as excavation and earth works, landscaping and external works, etc., of the project were sheduled by analysing the WWs, during the planing stage, even though the rain is considered as an Act of God and a totally uncertain event..
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Construction procurement selection: comparative study of public sector vs. private sector
Jayasena, HAEC; Rameezdeen, R
Construction procurement selection has been a major research area in recent past. Lots of researches have considered procurement selection by considering the overall construction industry as a one unit. Almost all the previous studies have identified the factors affecting procurement selection but a client wise consideration has not been carried out (Public sector vs. Private sector). Eg: Love et al, (1996), Masterman, (1992), NEDO et al, (1985), Luu et al., (2003), Chan et al, (2001). Since public sector and private sector play equally important roles in the construction industry, factors affecting procurement selection should be separately identified for each sector. Major reason for that is, although there are lots of procurement selection parameters have been identified, the importance level of those factors to the public sector selection may differ from private sector selection. That importance level can be very vital in selecting different types of procurement. Three rounds of Delphi surveys were conducted, to extract a set of exclusive factors and their levels of influence on public sector and private sector and to identify the suitability of available construction procurement options for each sector, with participation of a panel of experts who are engaged in procurement selection in the construction industry.
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Construction quality : Sri Lankan contractors perspective
Jayarathna, WTL; Senaratne
In today' changing environment, quality is the key to an organisation's success Many construction organisations have turn to adopt quality as a reliable management tool With this perspective, the research problem is articulated for this study as follows: How does the Sri Lankan construction contractors identify and utilize quality m their organisations . The research methodology adopted for this study was qualitative, within which case studies were used to investigate the research question. The primary data collection technique used in the case studies was semi structured interviews. Content analysis and cognitive mapping techniques were used to analyze primary data. The study identified several causes for poor construction quality and current practice of quality planning. The ISO 9000 quality’ management system ,s the most widely practicing or almost only system practicing in construction organisations, as it is a mandatory requirement acted by the ICTAD (Institute for Construction Training and Development). It was also identified that Sri Lankan construction industry is less exposed to new quality approaches such as total quality management, six sigma and benchmarking and etc. Several prerequisites for successful implementation of strategic quality planning in Sri Lankan context are also proposed including a strategic quality framework for construction organisations.
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Cost increases due to earthquake resistant detailing of concrete structures
Perera, DFU; Jayasinghe, MTR
There are two major factors that discourage the use of earthquake resistant design and detailing of structures constructed in Sri Lanka. They are the belief that the earthquake resistant structures will cost a lot more than the normal structures and the misconception that Sri Lanka is located at an area where no earthquakes will occur. On many occasions, the assumption that a particular area is seismically inactive has been proven wrong at the cost of human life and severe destruction to the infrastructure of an area. This is true for Sri Lanka as well since a number of earthquakes have been reported in the recent past in Central India and one event close to Sri Lanka which have hitherto be considered as seismically inactive. British Standard Codes of Practice used in Sri Lanka for structural design does not cover earthquake design and some of the reinforcement details widely adopted are not desirable with respect to earthquake performance. Earthquakes are among the most awesome of natural forces. They occur suddenly, generally without warning, and within 10-20 seconds can turn cities into wasteland. Most earthquakes around the world occur on well defined tectonic plate boundaries, and are known as inter-plate earthquakes. Earthquakes within a tectonic plate are called intra-plate and are spread across the whole of the plate rather than being confined to the boundaries. These occur less frequently. Since Sri Lanka is located away from well known plate boundaries, any earthquake occurring in Sri Lanka is intra-plate type. In an intra-plate area, it is almost impossible to predict the location or likely time of an earthquake event (Hutchinson et al., 1995). However, it is now widely accepted that the risk of earthquakes and their potential for damage especially in heavily populated areas can no longer be ignored. In summary an earthquake event in Sri Lanka may be considered to be low risk but of high consequence
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Design & construction of a low-cost furnace for melting non-ferrous alloys in the local foundry industry
Tittagala, SR; Navarathna, NPNM
A study has been carried out on the types of construction and factors affecting efficiency of metal melting furnaces currently used in the non-ferrous foundry sector with the objective of developing an oil-fired furnace with improved efficiency and reduced constructional and operating costs. The project was initiated by the FDSI (Foundry Development and Services Institute) to meet a requirement of the small and medium-scale foundry industry. For example, there are many manufacturers of ornamental castings of Brass and Aluminum in the country, but they face the problem of the absence of a suitable furnace which could operate easily, efficiently and economically. Following a preliminary survey and assessment of technical data, the main factors which affect performance were identified. Based on this a new design was evolved, the main features of which are that the charge is pre-heated, the flame retained in the furnace for longer duration and the fuel pre-heated and subjected to better atomised spray. The furnace, commissioned at a local foundry, demonstrated a significant improvement in performance over conventional types and acceptance by industry. A key feature was the improvement in overall working conditions and working environment. Based on this experience, a further improved version has been constructed and installed at the Mechanical Engineering Department - University of Moratuwa as a demonstration model for industry.
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Design and construction of a sundial
Hettiarachchi, N
Sundial is a very simple instrument used to read time. The principle is the motion of the sun during sunrise and sunset. Usually a shadow of a stick or an edge can be set to fall on a calibrated dial so that during the course of sun's motion in the daytime the shadow also travels on that dial indicating time at any instance. Unlike in usual clocks, sundials have an anticlockwise dial.
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Design of multi channel television receiving antennas
Jayasinghe, JASK
Since the introduction of Television to Sri Lanka in 1979, television viewers in Sri Lanka now have an opportunity to tune into seven TV channels. The island wide coverage of these channels has been achieved by the use of 24 transmitters. Some operators have one transmission station for island wide coverage and others use four to six transmission stations scattered around the country for island wide coverage. This has created a serious problem to the TV viewer, when selecting a suitable antenna. The problem is further complicated by the lack of awareness of the public. Therefore, many antenna manufacturers and vendors have exploited this situation and earn undue profits by selling variety of antennas without any technical details essential for deciding the suitability of the antenna for a particular location.
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Design of multi channel television receiving antennas
Jayasinghe, JASK
Since the introduction of Television to Sri Lanka in 1979, television viewers in Sri Lanka now have an opportunity to tune into seven TV channels. The island wide coverage of these channels has been achieved by the use of 24 transmitters. Some operators have one transmission station for island wide coverage and others use four to six transmission stations scattered around the country for island wide coverage. This has created a serious problem to the TV viewer, when selecting a suitable antenna. The problem is further complicated by the lack of awareness of the public. Therefore, many antenna manufacturers and vendors have exploited this situation and earn undue profits by selling variety of antennas without any technical details essential for deciding the suitability of the antenna for a particular location.
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Determination and suitable remedial treatment methods of accident prone locations (blackspots) in the city of Colombo (Sri Lanka)
Ratnayake, LL
The phenomenon of accident black spots has been recognised for many years. There is also considerable evidence to support the contention that the identification and remedial treatment of such sites proves extremely cost effective in accident reduction terms. David Silcock (1984) reported that in a County Council in U.K. an average first year Economic Rate of Return (ERR) of 148 percent was obtained for 147 black spots treated in the area. Nevertheless, the black spots approach to accident reduction represents only one of a number of low - cost engineering strategies in the road safety field. In this method, the locations where heaviest concentration of accidents occur are identified as those which require urgent attention, and remedial measures are carried out with economic justification.
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Developing a database for timber used in Sri Lanka
Hettiarachchi, MTP
Until recently timbers used for Structural purposes were limited to timber species that had been “tried and tested” over a long period of time. Today, however, these timbers are scarce and expensive, and it has become necessary to use either lesser known indigenous timber species or imported varieties of timber. The lack of easily accessible information on the local varieties of timbers has led to a reluctance by some potential users of timber to use the indigenous varieties for structural purposes. Information relating to different aspects of nearly 300 indigenous species is available from different sources. There is however a need to collate and integrate this information and present it in an easily accessible single source. A database is a suitable form of storage of the information, since it not only stores the information in an easily retrievable format that can be updated but also can be queried, to select suitable species for specific end uses or to find suitable end uses for a given species
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Developing a database for timber used in Sri Lanka
Hettiarachchi, MTP
Until recently timbers used for Structural purposes were limited to timber species that had been “tried and tested” over a long period of time. Today, however, these timbers are scarce and expensive, and it has become necessary to use either lesser known indigenous timber species or imported varieties of timber. The lack of easily accessible information on the local varieties of timbers has led to a reluctance by some potential users of timber to use the indigenous varieties for structural purposes. Information relating to different aspects of nearly 300 indigenous species is available from different sources. There is however a need to collate and integrate this information and present it in an easily accessible single source. A database is a suitable form of storage of the information, since it not only stores the information in an easily retrievable format that can be updated but also can be queried, to select suitable species for specific end uses or to find suitable end uses for a given species.