ICCEA-2019http://dl.lib.uom.lk/handle/123/162432024-03-28T13:51:54Z2024-03-28T13:51:54ZThree storied terrace houses with an insulated rooftop for tropical climatic conditionsMadurangi, MMNJayasinghe, MTRhttp://dl.lib.uom.lk/handle/123/163002022-06-21T09:13:49Z2019-01-01T00:00:00ZThree storied terrace houses with an insulated rooftop for tropical climatic conditions
Madurangi, MMN; Jayasinghe, MTR
With the growing population, there can be seen many developments in the construction field in recent times. People tend to move to the city areas seeking more facilities. However, this has been very difficult due to the high cost of land and construction. Although high-rise residential buildings (apartments) may seem to be a good solution, being an Asian country, most of the middle-class people are reluctant to live in these apartments due to cultural and social problems related to congested life. Therefore, to maximize the effective use of urban and suburban land, while providing private garden space for each house, a three storied terraced housing with an insulated rooftop that will allow the creation of a garden at rooftop level will be a winning option. The main advantage of such terrace housing is that it is ability to satisfy all the relevant building regulations applicable to create liveable houses with a land area of less than 100m2 per house (or less than 4 perch). Thus, when the land prices are very high, still it is possible to keep the overall costs lower since only a relatively smaller land area is now required to have a comfortably large house with a roof top garden. The roof top garden can allow regaining the land lost for the footprint of the house and hence can be considered as an attractive option. In this paper, the desirable concepts that can be followed to create thermally comfortable free running occupied spaces is described by considering the salient points of a warm humid tropical climates with low diurnal temperature variations. The various passive features that can be incorporated to various types of terrace housing also have been discussed in detail. Since Sri Lanka is having many variations of tropical climatic conditions varying from warm wet, warm dry and tropical uplands, such a development could provide a representative sample of possibilities that could occur in the tropical belt of the world in counties located on either side of the equator
2019-01-01T00:00:00ZLow cycle fatigue behaviouir of steel/ CFRP composite exposed to loads with constant amplitude.Abeygunasekera, SGamage, JCPHFawzia, Shttp://dl.lib.uom.lk/handle/123/162992022-06-21T09:13:55Z2019-01-01T00:00:00ZLow cycle fatigue behaviouir of steel/ CFRP composite exposed to loads with constant amplitude.
Abeygunasekera, S; Gamage, JCPH; Fawzia, S
This paper aims to investigate the fatigue performance of CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate under the three point flexural fatigue. CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate subjected to low cycle fatigue (LCF) to estimate and compare fatigue strength gain with respect to un-strength steel structures. Normal modulus (240 GPa) unidirectional CFRPs were used. Two test series were performed in this test series. A constant loads amplitudes cyclic load is applied on specimens with 2 kN magnitudes and 5 Hz frequency. The Coffin-Manson relation was used to explain the theoretical behaviour of LCF cycles. CFRP strengthened steel indicated a significant improvement in the fatigue life. This retrofitting technique reported significant fatigue strength gain; in the range between 26.8 % and 36.52 %.
2019-01-01T00:00:00ZInnovative reusable lightweight cement blocksMahaarachchi, TNPerera, SVTJhttp://dl.lib.uom.lk/handle/123/162982022-06-21T09:14:49Z2019-01-01T00:00:00ZInnovative reusable lightweight cement blocks
Mahaarachchi, TN; Perera, SVTJ
The cement blocks are a prefabricated material mainly used to build masonry walls in construction industry. Self-weight of units, workmanship and construction time are key factors affecting the masonry wall construction. The constructing of walls, ensure that the cement blocks are properly aligned with one another and need the skilled and highly paid masons for these masonry works. Considering these facts, the interlocking block masonry offer great advantage in masonry construction. The main feature of this interlocking block system is elimination of mortar layer with the tongue and groove method of the interlocking block. The demand of natural sand in the construction industry has increased due to the reduction of sources and an increase in price. Although, the self-weight of the structure can be reduced by introducing the hollow nature for the masonry blocks and also cost of the construction materials can be reduced due to the reduction of volume of the cement block. The goal in any interlocking system is to ensure efficient construction formation with well aligned masonry structures without skilled masons. Therefore, construction cost can be reduced due to the low skilled workers. Furthermore, the interlocking nature of these innovative blocks can be used for the reusable block. This paper presents an experimental investigation was carried out to introduce a new shape of cement block with interlocking behaviour for masonry wall construction, to fulfil the above-mentioned requirements. The interlocking hollow blocks developed were 390mm × 200mm × 190mm in size with a weight of 21.05 kg. The experimental investigation has shown that average compressive strength of block was 3.25N/mm2 and wall panel strength was 0.93N/mm2, therefore it can be used for load bearing masonry walls. It was also observed the innovative block is economical than conventional blocks.
2019-01-01T00:00:00ZRapidly constructed two storey thermally comfortable houses for tropical climates with light weight loadbearing concrete panelsEric, TBGunawardana, SGWHasalanka, HHHJayasinghe, MTRDamruwan, HGHhttp://dl.lib.uom.lk/handle/123/162972022-06-21T09:14:41Z2019-01-01T00:00:00ZRapidly constructed two storey thermally comfortable houses for tropical climates with light weight loadbearing concrete panels
Eric, TB; Gunawardana, SGW; Hasalanka, HHH; Jayasinghe, MTR; Damruwan, HGH
Apartments in tall buildings are often promoted as a solution to rapid urban migration that is happening in the world. However, all the apartment houses that have been undertaken in many parts of the world in large cities have not resulted in desirable results all the time. Therefore, it would be prudent to have high-density developments on small blocks of land with detached or semi-attached housing. Such high-density developments will be a special challenge in tropical climates when the urban heat island effects are considered since a high density of houses can often lead to lack of green cover, and hence to have somewhat higher temperatures than the averages predicted for that locality.
The other biggest challenge that is faced in countries with tropical climatic conditions is the extensive use of natural resources based walling materials like fired clay bricks, concrete blocks, etc.; this practice has led to over-exploitation of natural resources and hence it is prudent to explore the possibility of using alternative sources that will use much less amount of natural resources. In this context, converting various types of waste materials to a useful building material will also play a major role. One such material is the lightweight concrete panels produced to have 70% of the volume as air using recycled already used Expanded Poly-Styrene (EPS) panels manufactured in modular form with the dimensions of 0.6 m of length, 2.4 m of height and in thicknesses of 75 mm, 100 mm, 150 mm, etc. The use of panels instead of individual small units will allow rapid construction of a house, and it is shown that it is possible to complete one such house having about 200 m2 with a rooftop terrace in less than 30 working days by employing 6 Nos of semi-skilled workers.
In a detailed study carried out on with the tropical climatic conditions prevailing in Sri Lanka as a case study, it is shown that there are so many strategies that can be very effectively used to make such houses extremely thermally comfortable while almost eliminating the heat island effects even if a high density has been achieved with individual blocks as small as 200 m2. The research paper is intended to describe all these aspects by taking an actual two storey house with roof terrace constructed in Sri Lanka in the wet zone.
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