Browsing by Author "Thenuwara, HV"

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item: Conference-Full-text
Applicability of gneiss based mineral aggregates for the use in high friction surface treatment in terms of polishing characteristics
(Springer, 2021) Thenuwara, HV; Buddhi, PHGH; Pasindu, HR; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Speed and safety management of highways plays a prominent role in ensuring road user safety, especially of the vulnerable categories. Pavement Friction Management (PFM) is being considered as the best possible option in developing the road infrastructure over the other prevalent strategies, with the focus of improving user safety. High Friction Surface Treatment (HFST) is widely being used as a remedial measure to improve the friction and texture retention capacity of the wearing course, as it provides economical and sustainable solutions in upgrading the pavement performance in both as an urgent response and in the long run as well. As an urgent remedial intervention, HFST can be incorporated in the national practice of safety management in Sri Lanka, to address the concerns over the escalating numbers of grievous highway crashes. In place of the most commonly used high skid resistant aggregates, gneiss-based mineral aggregate can be a viable alternative since it delivers similar functionality to that of granites. The study examines the polishing characteristics of widely used gneiss-based roadstones in the country through laboratory experiments involving the Polish Stone Value (PSV) test. Both qualitative and quantitative analyses of the specified physical and mechanical laboratory testing are conducted to evaluate the applicability of gneiss-based mineral aggregates in the use of HFST as an alternative skid-resistant roadstone in terms of their polishing behavior.
item: Conference-Full-text
An assessment of the polishing behaviour of road surfacing aggregates in Sri Lanka
(Springer, 2021) Thenuwara, HV; Jayasuriya, WWC; Pasindu, HR; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
Friction capacity between the tire-pavement interface, facilitates sufficient braking force ensuring road user safety. Inadequate skid resistance has been identified as the prominent pavement-related cause of highway crashes. Availability of friction at the wearing course is governed by pavement, vehicle and tire/driver condition parameters combined with environmental parameters, of which pavement-related characteristics concern a greater proportion. Crucial pavement-related characteristics include mineralogical and textural properties of road surfacing aggregates, where the polishing behaviour of coarse aggregates exhibits significant influence in the establishment of skid resistance of asphalt concrete pavings. Thus, many research have been conducted to determine the suitability of aggregates, in terms of resistance to polishing under trafficking. In the national context, broader attention is being developed towards road safety as one of the critical performance parameters due to the integration of an expressway system with the prevailing road network. However, the amount of such extensive study into pavement friction and properties of locally available aggregates, is scarce. No guidelines considering user safety have been specified in the Standard Specifications for Construction and Maintenance of Roads and Bridges by the Institute for Construction Training and Development, Sri Lanka. Therefore, initiatives to incorporate skid resistance in the national practice of aggregate selection for pavement construction, are indispensable. Hence, this study aims to establish the friction characteristics of Sri Lankan natural roadstones, through the Polish Stone Value Test involving the Accelerated Polishing Machine and the British Pendulum Tester, and to evaluate the observed polishing patterns through a petrographic analysis and microscopic investigation.
item: Conference-Full-text
Methodology to incorporate frictional performance in the pavement management system of Sri Lankan expressways
(IEEE, 2020-07) Thenuwara, HV; Pasindu, H; Edussooriya, C; Weeraddana, CUS; Abeysooriya, RP
In Sri Lankan context, renovations or reconstruction of road overlays are carried out mainly based on visual measurements of the pavement condition such as settlements, potholes and other prominent signs of deterioration. Though the above practice may be acceptable in the point of view of low volume roads, expressways with higher design speed require frequent monitoring rather than unplanned, immediate rehabilitations. Pavement Management System (PMS) becomes important to recommend necessary conservative measures for effective management of the pavement with the use of various decision making/supportive tools and mechanisms. Identification of the critical friction related pavement characteristics and introducing methodologies to interpret such, is a must in order to formulate a method to incorporate Friction Management Programme (FMP) in the PMS. The paper suggests basic threshold values (investigatory and intervention) of friction and texture for Sri Lankan expressways, through an analysis of the deterioration rates of pavement friction. Analysis is carried out comparing the reference graph of pavement friction deterioration curve derived through laboratory experiments involving Accelerated Polishing Machine and the British Pendulum Tester, together with the graph obtained from the survey data of the Southern Expressway.