Browsing by Author "Arandara, KP"

Now showing 1 - 9 of 9

item: Thesis-Abstract
Durability properties of earth buildings
Arandara, KP; Jayasinghe, C
Soil was a popular building material in Sri Lanka with many indigenous construction techniques. Although there were many houses constructed with soil based materials in the ancient times, burnt clay bricks and cement blocks have overtaken the indigenous walling materials in the recent past. However, with the prevailing sand crisis and environmental problems associated with modem construction methods, stabilized earth has been again introduced to Sri Lanka with some technological advancement. With extensive researches carried out on compressed stabilized earth blocks and rammed earth, the strength characteristics of both these materials were proven adequate for load bearing masonry construction. Recently, however it has been thought that it would be architecturally desirable to leave earth walls without any exterior coating, and this has given rise to questions on long-term resistance to driving rain. The research presented in this thesis was organized and aimed at assessing the durability properties of various forms of stabilized earth constructions and to develop improvements with cost effective paints and/or plasters. In order to achieve the above objectives, the following methodology was adopted. Firstly, a detailed literature review was carried out to investigate the durability enhancement techniques that have been successfully adopted for earth construction in Sri Lanka and other countries. Secondly, a field survey was carried out to identify durability problems with earth buildings already constructed in Sri Lanka. The wall panels were constructed out of compressed stabilized earth blocks and rammed earth to carry out the durability testing, specified in the relevant Codes of Practices and Earth Building Standards. Different paints and plasters were applied on earth wall panels and accelerated durability testing was conducted on panels with erosion test apparatus. The durability improvements suggested in this study includes provision of long eaves, adequate stabilization levels, suitable protective coatings and strategies to minimize shrinkage that can be applied in the design and construction stages. Such measures will certainly ensure more durable structures built with stabilized earth as a walling material. However, areas subjected to flooding needs special care in terms of durability. Therefore, special designs should be introduced for the houses built in such locations. The study revealed that 5% cement can be recommended as the optimum in terms of durability aspects. Using durability testings, different surface coatings were assessed for durability aspects. It was found that best combination is cement plaster and emulsion or weather shield paint. The coatings like mud paint on a plaster and Acrylic filler directly on blocks can be recommended in relatively dry areas or for walls adequately protected by eaves. Thus, it can be stated that walls constructed with cement stabilized earth blocks or rammed earth can be either kept exposed with a suitable paint based protection or applied with a plaster of minimum thickness. The machine made blocks allow attractive finish even without plastering and hence allow reaching one of the key goals in sustainable construction of minimizing the use of natural resources.
item: Conference-Full-text
Evaporative cooling for occupational health in tropical climates
(Department of Civil Engineering, University of Moratuwa, 2011-12) Arandara, KP; Jayasinghe, C; Jayasinghe, MTR; Ratnayake, N
Occupational health is a cross disciplinary area concerned with protecting the health of people engaged in work or employment. If is increasingly becoming a serious concern for industries and companies to safeguard the well-being of their employees. When address the physical hazards under occupation health, provision of thermal comfort is very important, especially to avoid hyperthermia condition which could be a vital issue in tropical climates. Hlence, there should be a HVAC system like Evaporative cooling which has best performances in terms of thermal comfort as well as the occupational health. Evaporative cooling is a best alternative for providing thermal comfort environment as it is very much energy efficient and also it could control the spreading of Biological hazards such like bacteria, virus and fungi.
item: Conference-Full-text
Evaporative Cooling for Occupational Health in Tropical Climates
(2016-05-26) Arandara, KP; Jayasinghe, C; Jayasinghe, MTR
Occupational health is a cross disciplinary area concerned with protecting the health of people engaged in work or employment. If is increasingly becoming a serious concern for industries and companies to safeguard the well-being of their employees. When address the physical hazards under occupation health, provision of thermal comfort is very important, especially to avoid hyperthermia condition which could be a vital issue in tropical climates. Hence, there should be a HVAC system like Evaporative cooling which has best performances in terms of thermal comfort as well as the occupational health. Evaporative cooling is a best alternative for providing thermal comfort environment as it is very much energy efficient and also it could control the spreading of Biological hazards such like bacteria, virus and fungi.
item: Conference-Full-text
Performance of evaporative cooling systems with chilled water
(2013-11-12) Arandara, KP; Jayasinghe, MTR
Many climatic records indicate that the average temperature of many countries have increased at least by one degree and also have changed the rainfall pattern to a certain extent. These have made the conditions in warm humid tropical countries somewhat undesirable. With improved economic conditions in many countries in the Asian region, a shift to air conditioning can be seen in office buildings, factories and houses. An energy efficient alternative to air conditioning is the use of evaporative cooling. However, its performance in months with higher moisture content that results in higher relative humidity cannot be efficient and hence there is a barrier for its popularization. One option available is the use of chilled water for improved performance. This research highlights the thermal performance that can be achieved with chilled water and the responses that have been obtained from the workers of a large factory complex located in Sri Lanka where the humidity ratio can reach 0.018 during some months.
item: Conference-Full-text
A review on utilization of c & dwaste for road and pavement construction in the international context and applicability of the findings to Sri Lanka
(Springer, 2021) Arandara, KP; Priyadarshana, ST; Paranavithana, GN; Dissanayake, R; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
In this paper, the utilization ofC&D(Construction and Demolition)waste for roads and pavements construction is reviewed in the international context. Further, the results are assessed to see the relevance to Sri Lanka. The relevant references gathered from the databases are referred to this study. The different countries and regions including Asia, Australia, Middle-East, Europe, and the USA, are covered with 67 papers. Those references are critically reviewed by applying PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) methodology and key C & D waste types utilized for roads and pavements construction are found out. The paper discusses Recycled Concrete Aggregates (RCA), Crushed Clay Bricks (CCB), and Recycled Asphalt Pavement (RAP) as the C & D materials that commonly are used for roads and pavements construction. Also, policies, laws, regulations, and procedures adopted in multiple countries, applicable to the C & D waste sector are discussed in the paper. The findings are evaluated in the latter part of the paper and proposed applicability/rationales to Sri Lanka are examined simultaneously. The authors conclude that the specified three types of CDW based recycled materials could be utilized across the cross-section of roads and pavements through effective methods and applications in several counties and the same approach is applicable in Sri Lanka also. This study confirms that very significant policy support in terms utilization of CDWis evident in most countries and the particular learnings could be applied in Sri Lanka to improve the current state appropriately.
item: Article-Full-text
Surface Coatings for Stabilized Earth Walls
(2016-05-26) Arandara, KP; Jayasinghe, C
Wall construction with stabilized earth in houses and low-rise buildings in becoming popular with the promotion of sustainable concepts in the construction industry. Many studies conducted on strength properties of stabilized earth have shown this material is strong enough for the load bearing of two or three story construction with engineering design. Durability is another key parameter of a walling material. This paper covers the outcome of a detailed study conducted on durability of stabilized earth as a walling material. This include, levels of stabilization necessary to improve durability, the performance of different surface coatings applied on earth walls and testing of surface coatings on durability properties according to the relevant accepted standards. Two types of stabilized earth walls were considered in the study, such as compressed stabilized earth blocks and stabilized rammed earth. With the findings of the study covered in this paper now it is selected surface coatings for different levels of durability of earth walls, required by the clients. Further the necessary stabilization levels can be selected to maintained both strength and durability.
item: Conference-Abstract
Sustainable road construction with compressed stabilized earth
(2016-09-07) Arandara, KP; Jayasinghe, C; Jayasinghe, MTR
Heat island effect has been given significant recognition in LEED certification process. The idea is to reduce the heat island effect to minimize impacts on micro climates and human and wild life habitats. In this context, it is useful to have roads with Solar Reflectance Index of more than 29% and also less than 50% impervious. Cement stabilized earth has the potential to satisfy this requirement as an alternative to asphalt paved roads. This paper describes some field experience gained while constructing a cement stabilized earth road with adequate strength and durability
item: Conference-Full-text
Sustainable road construction with compressed stabilized Earth
(2013-11-15) Arandara, KP; Jayasinghe, C; Jayasinghe, MTR
Heat island effect has been given significant recognition in LEED certification process. The idea is to reduce the heat island effect to minimize impacts on micro climates and human and wild life habitats. In this context, it is useful to have roads with Solar Reflectance Index of more than 29% and also less than 50% impervious. Cement stabilized earth has the potential to satisfy this requirement as an alternative to asphalt paved roads. This paper describes some field experience gained while constructing a cement stabilized earth road with adequate strength and durability.
item: Conference-Full-text
Thermal comfort with evaporative cooling for tropical climates
(2013-11-21) Arandara, KP; Attalage, RA; Jayasinghe, MTR
The tropical climatic conditions that prevail in the countries located close to the equator generally has warm humid climatic conditions. This high humidity generally results due to the relatively high moisture content in the atmosphere. It is shown that warm humid climatic conditions can still offer a good possibility for the use of evaporative cooling when the beneficial effect of evaporative cooling is coupled with physiology cooling effect that is available with enhanced indoor air qualities