Browsing by Author "Lewangamage, S"

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item: Article-Full-text
Investigation of pozzolanic properties of sugarcane bagasse ash for commercial applications
(American Chemical Society, 2023) Prabhath, N; Kumara, BS; Vithanage, V; Samarathunga, AI; Sewwandi, N; Damruwan, HGH; Lewangamage, S; Koswattage, KS
The ideal climatic and environmental conditions for sugarcane cultivation are present all year round in the tropical island of Sri Lanka. Given the annual sugar consumption of the nation, a significant amount of sugarcane bagasse ash (SCBA), a by-product with no intended commercial use but potential environmental and health risks, is produced. Numerous studies have been conducted recently to assess the viability of using SCBA as a pozzolanic material in structural applications. The purpose of this study is to evaluate the microstructure of SCBA samples from three sugar manufacturing facilities in Sri Lanka to identify the pozzolanic capacities. Several quantitative and qualitative characterization techniques have been utilized for the investigations. While maintaining the American Society for Testing and Materials (ASTM) 618 specification as the standard for pozzolanic properties, a comparative investigation of the attributes of samples from each location was conducted. Beyond that, the relationship between the SCBA generation process parameters and their impact on the properties of SCBA have been identified. Finally, the SCBA source of the Pelwatte unit has been identified as the ideal source for the pozzolanic material from the three locations, considering quality and the extent of additional treatments required before use. Other prospective areas of research on SCBA and its potential applications have been recognized.
item: Conference-Full-text
Study on the cracks developed in Dematamal Viharaya, Uva Province Sri Lanka
(2013-11-26) Paskaran, S; Perera, M; Kumara, D; Jayasinghe, T; Jayasinghe, C; Lewangamage, S;
Stupas of Sri Lanka stand as proud examples for the engineering Excellence of ancient Sri Lanka. Dematamal Viharaya at Butthala is one of the oldest Stupas in Sri Lanka built in the 2nd Century BC. It is a, 19m tall non-plastered brick structure. This Stupa has developed since 1998. Cracks have initiated from the Pesawalalu and propagate to the top of the Dome. The width of these cracks varies from 0.2mm to 0.5mm. The research covered in this report is aimed at the identification of the causes for the cracks and to propose corrective actions. A comprehensive study was carried out to identify the possible causes for the cracks which may be due to self weight and shape of the stupa, expansive nature of soil, arch action induced due to separation of old and modern masonry. Experiments were done to assess the expansive nature of the soil and A Finite element analysis was carried out using the Finite element software SAP2000. The results revealed that the possible cause can be the arch action induced due to separation of old and modern masonry. Increasing the bearing of the new brick work at the base and the installation of a tie beam around the pesawalalu are the two corrective actions suggested in this report.
item: Conference-Full-text
Ultimate strength prediction for reinforced concrete slabs externally strengthened by Fiber Reinforced Polymer (FRP)
(Department of Civil Engineering, University of Moratuwa, 2011-12) Sivarajah, A; Abeysinghe, A; Lakshitha, M; Lewangamage, S; Ratnayake, N
This paper presents the potential use of externally bonded fiber reinforced polymer (FPR) systems to upgrade reinforced concrete slabs deficient in flexural strength. A total of five slabs, each having 500 mm width, 125 mm thickness, and 1530 mm length, were cast and tested to failure under four-point bending. Two slabs were reinforced with three number of 10 mm tor steel bars at the tension side that corresponds to 0.38% steel reinforcement ratio. One slab was used as a control whilst the other slab was strengthened with fiber reinforced polymer (FRP). Other three slabs were reinforced with four numbers of 6 mm mild steel bars at the tension side that corresponds to 0.18% steel reinforcement ratio. One slab was used as a control specimen while the other two slabs were strengthened with different arrangement of fiber reinforced polymer (FRP). In the experimental stage, the influences of FRP on the slabs were analyzed by studying their behaviour at failure.