Browsing by Author "Galkanda, H"

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item: Conference-Full-text
Improve intrinsic properties of walling materials to create occupant comfort
(2018) Galkanda, H; Udawattha, C; Halwatura, R; Samarawickrama, S.
Abstract Buildings and architectural spaces are built for occupant comfort. Thus tropical climatic condition is the worst climate to achieve the occupant comfort. Tropics are favourable for bio receptive activities such as fungus and moss. Fungus and moss produce mycotoxins, spores and fragments which are toxic to occupants. However, the relationship between buildings envelops and bio receptivity should be studied prior to find a sustainable solution. This study was conducted to understand the relationship with intrinsic properties of wall construction materials and the bio receptivity. The study was conducted after studying several intrinsic properties of walling materials such as organic matter content, surface roughness, water absorption and pH value according to laboratory test standards. Fungus and moss growth standard tests were conducted in the real world-controlled environment. Results of this study showed that surface roughness is the significant intrinsic property on bio receptivity. According to the test results fungus and moss growth on walling materials has a reciprocal connection with surface roughness values and no growth occurs on wall plasters where the surface is smoother. This study concluded that covering walls with cement plaster can reduce the growth of moss and fungus on tropical homes. Therefore smooth, plastered surfaces are best for homes with occupant comfort. But the cost of plastering might prevent poor families from acting on this concept. Therefore it is necessary to develop sustainable, cost effective and environmentally friendly wall, smoothing materials and techniques.
item: Conference-Full-text
Investigation of mechanical properties of mud concrete with coconut fiber reinforcement
(IEEE, 2020-07) Galabada, H; Galabada, PD; Galkanda, H; Halwatura, RU; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
Mud concrete was a sustainable innovation, invented to replace existing conventional construction materials with sustainable material. Mud concrete consists of soil and cement along with water. In terms of sustainable construction, cement which act as the stabilizer in mud concrete should be kept lesser as much as possible, according to its potential environmental issues. Therefore, evaluation of ability to enhance the mud concrete properties by adding some admixtures is essential. There are no of admixtures used in the construction industry with many forms, such as liquid, solid, semisolid or fiber. In most of the studies fiber was used as an admixture to improve the strength performance of construction materials. Hence, evaluate the strength performance of mud concrete with fiber is important to reduce cement in sustainability contest. Therefore, this study was investigated the effect of natural fiber length on compressive strength and strength variation with water content of mud concrete with fiber. According to the results, the highest strength was recorded with the fiber length of 60 mm and the compressive strength was decreasing with the increasing water content. The study concluded that the optimum fiber length is 60 mm and there is a negative correlation between compressive strength and water content.
item: Article-Full-text
Mold growth and moss growth on tropical walls
(Elsevier, 2018) Udawattha, C; Galkanda, H; Ariyarathne, IS; Jayasinghe, GY; Halwatura, R
The tropical climatic condition is the worst climate condition for building materials [1] [2] [3] [4]. Because, the tropics consist of rain, sun, high humid wind etc. [5] [6] [3]. The idea of the wall and roof are to protect human beings from these environmental constraints [4] [5] [6]. Hence, the capacity confronts those environmental constraints by the roof and wall are very important [7] [8] [9]. Not only environmental constraints but also there are other effects due to those environmental constraints such as weather degradation, scaling off the materials, natural decay, mold growth and moss growth. Molds can be found everywhere and can grow on any material in the presence of moisture. The growth of the mold is due to the pores. When the pores land on building materials they start to reproduce all over the material. Mold can be found in indoor climate as well as the outdoor climate. But the most dangerous mold can be found in indoor produced series of health problems due to a particle size of the mold [10]. Moss growth is subject to outdoor environments except in case of a water leak, which can be found in indoor climates. Moss growth is a common phenomenon in tropical climatic conditions. Moss growth is accelerated due to the rainy weather and stabilized by the materials property. For instant moss, brick is easily subjected to moss growth. The effect and the growth rate of mold and moss are not properly studied in tropical climatic conditions (See Table 1). Tropical climatic condition is the most favorable climate for mold and moss growth. Therefore it is essential to understand the causes of mold and moss growth in tropical walling Material.
item: Article-Full-text
Performance of natural polymers for stabilizing earth blocks
(Elsevier, 2018) Udawattha, C; de Silva, DE; Galkanda, H; Halwatura, R
Natural polymers have been tested for soil stabilization since prehistoric age. This study evaluated the behavior of seven natural polymers as earth stabilizer. Seven polymers were selected from Sri Lankan vernacular polymer technologies. Natural Polymers were extracted from plants and trees. And then mix designs were developed by mixing soil and natural polymers (5, 10, 15 and 20%) by the dry weight. Compressive strength was subjected to understand the initial performance of each natural polymer. And the series of performance tests were conducted to understand the engineering and mechanical performances. The initial experiment shows only three natural polymers are suitable for stabilizing earth blocks such as pines resin, Dawul Kurudu, and sugarcane bagasse. And then different soil mix design experiment shows that natural polymers are good at gaining strength when soil particles are smaller (15% gravel sieve size 4.25–20 mm, 80% sand sieve size 0.425–4.25 mm, and 5% fine sieve size below 0.425 mm). Maximum compressive strength with pines latex was given as 2.65 N/mm2. It reached the construction material required the dry strength of 2 N/mm2 and wet strength of 1 N/mm2. Further studies should be conducted to understand the bond development and e values of selected polymer stabilized earth blocks.
item: Conference-Full-text
Thermal performance comparison on flooring materials
(Faculty of Architecture Research Unit (FARU), 2021-12-03) Galabada, GH; Dharmaratne, PD; Galkanda, H; Halwatura, RU
New building materials and technologies that provide thermal comfort are expected to gain popularity in the recent past. Hence, efforts to incorporate new building material solutions are needed to protect potential populations from the threats of thermal stress that cause an increase in temperatures due to climate change. The earth is identified as the most effective building material to improve the thermal comfortability inside the building. Among several building construction materials, the flooring material provides a more effective role with respect to thermal comfort in a building. This paper present the evaluation and comparison work carried out to investigate the thermal performance of newly invented soil based flooring material with other common floorings in Sri Lanka. Temperature measurements were taken on the top surface of flooring materials and were compared the surface temperature of each other and indoor air temperature. The results reveal that the soil floor shows a lesser temperature at a significant level than the other floorings. Hence, it can be proved that the building construction materials play an important role and earth is the best sustainable material with respect to the indoor thermal comfortability thus, end-user.