Browsing by Author "Selvaranjan, K"

Now showing 1 - 5 of 5

item: Conference-Abstract
Development of a novel waste based insulated plaster with water proofing ability for roof slabs
(Department of Civil Engineering, 2023-09-27) Weerakkody, DD; Gamage, JCPH; Chandrathilaka, ERK; Selvaranjan, K; Mallikarachchi, C; Hettiarachchi, P; Herath, S; Fernando, L
The cement industry, notorious for its significant contribution to global greenhouse gas emissions, has drawn increasing attention in recent years due to its environmental impact. As we strive to combat climate change, one crucial area of focus is improving the thermal performance of buildings, which not only reduces energy consumption but also enhances thermal comfort for occupants. Among the various components of a building's thermal envelope, roof slabs stand out as key contributors to heat transfer, accounting for a substantial 50-60% of overall heat exchange. Addressing this thermal challenge necessitates innovative solutions, and one such solution that has gained attention is the use of Rice Husk Ash (RHA) as a sustainable material to augment thermal insulation in roof slabs. This approach aligns with the broader goal of sustainable construction practices and the reduction of greenhouse gas emissions by employing controlled waste disposal techniques that transform waste materials into timely-needed sustainable building materials. The core concept behind this novel approach involves the manipulation of the material's microstructure. To achieve low thermal conductivity, the RHA is employed to induce a pore structure within the material. This pore structure acts as a barrier to heat transfer, significantly enhancing the insulation properties of the roof slabs. Simultaneously, the gaps and voids within the microstructure of the material are filled with non-conductive Waste Brick Powder (WBP). This dual-purpose protection not only improves the thermal performance of the roof but also contributes to enhanced waterproofing abilities. The benefits of this innovative product are impressive, particularly when compared to existing alternatives available in the market. In a comparative analysis, this new material demonstrated a remarkable 69.5% reduction in thermal conductivity, making it an effective solution for minimising heat transfer through roof slabs. Moreover, it exhibited an outstanding 89% improvement in its waterproofing abilities, which is crucial for maintaining the structural integrity of buildings and ensuring the comfort of occupants. This groundbreaking development represents a significant stride towards sustainable construction practices. By harnessing waste materials like RHA and WBP, we not only reduce the environmental footprint of construction but also produce materials that enhance energy efficiency and comfort within buildings. As we continue to address the pressing challenges of climate change, solutions like these offer a glimmer of hope for a more sustainable and environmentally friendly future in the construction industry. In conclusion, the integration of Rice Husk Ash and Waste Brick Powder in roof slab construction is a pioneering approach that holds great promise for reducing greenhouse gas emissions, improving thermal comfort, and advancing sustainable construction practices. This innovation not only contributes to energy-efficient building design but also underscores the importance of repurposing waste materials to create valuable and environmentally responsible building materials.
item: Article-Full-text
Development of a plastering mortar using waste bagasse and rice husk ashes with sound mechanical and thermal properties
(Elsevier, 2022) Srikanth, G; Fernando, A; Selvaranjan, K; Gamage, JCPH; Ekanayake, L
The concept of using cleaner production technologies has become prominent in the present context for achieving sustainability in construction. Incorporating agricultural waste as cement replacements has shown enhanced mechanical and durability properties of the resulting mortar. A comparative study on the mechanical, thermal and environmental performance of a newly developed lightweight mortar containing agro-wastes namely Bagasse Ash (BA) and Rice Husk Ash (RHA) were investigated. Ordinary Portland Cement was partially replaced by BA at dosages of 0%, 5%, 15%, 20%, and 30% and RHA at dosages of 0%, 5%, and 15% by weight. A detailed investigation was carried out to determine the optimum material mix design which achieved good material properties. Results indicated that the addition of 30% BA as a partial replacement for cement improved the thermal performance by causing a 33% decrease in the thermal conductivity. Additions up to 30% of BA or 15% each from RHA and BA can be used to obtain mortar with compressive strengths complying with the standard values. At the same time, the combination of BA and RHA (15% each) decreased the thermal conductivity up to 31% compared to the conventional mortar. Further, the environmental assessment indicated that incorporation of BA and RHA in mortar can significantly reduce greenhouse gas emissions (i.e., 28% reduction per kg of BA).
item: Article-Full-text
Development of high strength recycled aggregate concrete-composite effects of fly ash, silica fume and rice husk ash as pozzolans
(Springer Science and Business Media LLC, 2022) Fernando, A; Selvaranjan, K; Srikanth, G; Gamage, JCPH
The world today has started facing bigger problems related to the concrete industry, especially with concrete becoming the most extensively used construction material in the world. At a time like this, where more eco-friendly substitutions are stringent, it calls for a more comprehensive approach in producing recycled concrete from recycled concrete aggregates (RCA). This study is an extension to previous studies involving composite utilization of pozzolans in treating RCA. It investigates on the possibility of using rice husk ash (RHA) along with other pozzolans as a cement replacement, in both stages of aggregate treatment and concrete production. It was observed that through this treatment, aggregate specific gravity was increased to a value of 2.37 which was earlier 2.18 for untreated RCA, 26% and 59% reductions were obtained for water absorption and porosity of aggregates, respectively. Further the concrete which contained RHA in both stages, attained a high strength of 55.4 MPa, even surpassing the control mix containing natural aggregates. The same mix resulted a 12% increase in its surface resistivity. Rapid Chloride Permeability Test (RCPT) and water permeability results also showed substantial improvements when compared to the reference RCA mix. Similar to previous studies involving composite use of pozzolans, improvements in the microstructure of both the aggregates and concrete through the use of RHA resulted in the amelioration of both mechanical and durability properties of concrete. This evidently indicates the possibility of achieving high strengths, even with the use of RCA derived from parent concretes of lower grades.
item: Conference-Full-text
Investigation of replacing aggregate with non-homogeneous waste tire rubber aggregate in concrete
(IEEE, 2022-07) Kuruwita Arachchi, VI; Gamage, JCPH; Selvaranjan, K; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
This article investigates the impact of using non-homogenous rubber aggregate on a developed concrete mix design. Identifying the dominant reasons and modifications to be made to improve the properties of rubberized concrete are discussed with respect to the diverse number of literatures. The recycled waste tire rubber particles were tested to identify the physical properties of rubber aggregate and twelve rubberized concrete cubes were tested in axial compression. The cubes were produced by replacing waste tire rubber with 1) 0% aggregate volume (Series 1) 2) 20% fine aggregate volume (Series 2) and 3) 10% coarse and 10% fine aggregates of the total aggregate volume (Series 3). The results show a high-water absorption rate of 6-7% in rubber aggregate. The compressive strength of cubes reached up to 48.6 MPa, 32.4 MPa, and 37.5 MPa in Series 1, 2, and 3, respectively. Implementing 10% coarse and 10% fine rubber aggregate enhanced the compressive strength by 10.5%. There is clear evidence on improved mechanical properties of rubberized concrete with the addition of non-homogenous rubber aggregates.
item: Article-Full-text
Thermal and environmental impact analysis of rice husk ash-based mortar as insulating wall plaster
(Elsevier, 2021) Selvaranjan, K; Navaratnam, S; Gamage, DCPH; Thamboo, J; Siddique, R; Zhang, J; Zhang, G
The energy used to maintain the thermal comfort of buildings significantly contributes to the GHG emissions and global warming. In this study, a sustainable and cost-effective rice husk ash (RHA)-based mortar for wall plastering has been developed to provide better thermal insulation, reduce the operational energy and enhance the thermal comfort. Consequently, RHA was partially replaced with the sand in the conventional mortar to produce the RHA-based plaster. Initially, compressive strengths and thermal conductivities of the selected mortar mixes were assessed. The results highlight that the RHA can be replaced up to 30% instead of sand in mortar to produce the thermally enhanced wall plaster. Further, two identical prototype model houses were constructed with RHA-based (i.e. 30% of RHA) and conventional plasters to evaluate their heat transfer, heat flux, and the characteristics of internal and external wall surface temperatures in open weather conditions. It was noted that the average peak heat flux reduction formed by the RHA-based plaster was 10%. The average daily heat transfer reduction across the wall with RHA-based plaster was about 26%. Results also show that RHA-based plaster can reduce the energy that required to maintain thermal comfort by about 9% than the conventional plaster. Moreover, the environmental impact analysis was also conducted to assess the sustainability performance of RHA-based mortars. The environmental impact assessment revealed that the RHA-based plaster has less environmental impact than the conventional mortar. Furthermore, the CO2 emission generated by the production of RHA-based mortar is about 14% less than the conventional plaster.