TRF - 2020http://dl.lib.uom.lk/handle/123/179572024-03-29T01:34:01Z2024-03-29T01:34:01ZTransport Research Forum 2020 (Pre Text)http://dl.lib.uom.lk/handle/123/205422023-10-13T02:35:25Z2020-01-01T00:00:00ZTransport Research Forum 2020 (Pre Text)
Perera, HLK
2020-01-01T00:00:00ZStrategies into practice through the pavement management systemGunarathna, PThananjeyan, Ahttp://dl.lib.uom.lk/handle/123/179882022-06-21T08:48:59Z2020-12-01T00:00:00ZStrategies into practice through the pavement management system
Gunarathna, P; Thananjeyan, A
Perera, HLK
Pavement Management System (PMS) is a set of procedures/methods available for collecting, maintaining, analysing, and reporting pavement data to assist the decision-making process.
When it comes to road maintenance planning, decision making is always challenging where road agencies have a limited budget to deliver their long-term strategies. This has put immense pressure on asset managers and asset Engineers to establish a process that priorities
maintenance treatments for better network outcome.
Prioritising maintenance needs of a road network based simply on its current condition failed to satisfy the long-term impact of the maintenance (IDS 2019). It is recommended to combine project prioritization and the budget optimization process to achieve a balance between the maintenance needs and budget constraints. The optimised program will ensure the best value
for money when analysing benefits of the desired maintenance options under a limited budget. The presentation will discuss the steps involved in developing the optimised road maintenance program for delivering long-term strategies and benefit of PMS for the long- term decisionmaking
process.
2020-12-01T00:00:00ZEffectiveness of demolished concrete waste for resurfacing of low volume roads in Sri Lanka using roller compacted concrete (RCC) technologyJayantha, WRANMampearachchi, WKhttp://dl.lib.uom.lk/handle/123/179872022-06-21T08:49:22Z2020-12-01T00:00:00ZEffectiveness of demolished concrete waste for resurfacing of low volume roads in Sri Lanka using roller compacted concrete (RCC) technology
Jayantha, WRAN; Mampearachchi, WK
Perera, HLK
Roller Compacted Concrete Pavement (RCCP) is a type of zero slump concrete product, which has renewed the interests of sustainable pavement designers with its potential to reduce the total cementitious material content of the concrete mix. RCC is produced with the same ingredients as in conventional concrete paving, but with different proportions determined by a suitable mix design approach. RCCP construction procedure is similar to that of asphalt paving, where laying is performed using a modified asphalt paver and steel drum rollers follow
the paver to ensure laid RCC mix to be compacted to its desired density. However, in low
volume road construction, motor graders can be used in place of modified asphalt pavers for the laying process since the degree of precision required is low.
Even though concrete pavements are durable in the norm, owing to poor construction practices
and improper maintenance, the concrete surfacing of low volume roads is at a stage in need of
rehabilitation. The current rehabilitation practice of the damaged concrete roads in Sri Lanka is
replacing the damaged pavement with a new surfacing, where the deteriorated concrete layer is removed as a landfill material or sometimes reused as a base for the new surfacing. However, full disposal of the damaged pavement and subsequent replacement with a new pavement is not an economically viable construction practice. The objective of this research is to evaluate
the applicability of deteriorated concrete pavement for the reconstruction of new pavement in an economical and sustainable approach.
In this study, manually crushed concrete slabs were washed, sieved, and tested for aggregate strength to be used as a substitution of coarse aggregates (CA) in RCC. Control samples were cast with the use of virgin crushed aggregates (VCA) and test specimens were prepared with
recycled concrete coarse aggregates (RCCA) in full replacement of CA. The mix proportions of the concrete mix were calculated using the soil compaction method, which focuses on the
optimization of the dry density of the RCC mix. Vibratory hammer test – ASTM D7382
(VHT) was used in place of the modified proctor test – ASTM D1557 (MPT) in determining
the optimum moisture content (OMC) of RCC concrete since an impact compaction test does not exactly simulate the actual site condition at the mix design stage.
The dry density of RCC test specimens was found to be very sensitive to moisture content
when the compaction was coupled with vibration. VHT resulted in higher density and lower
OMC while MPT produced almost the same density at a higher OMC. However, the actual site compaction practice involves a combined effect of vibration and impacts. A compressive strength over 20MPa can be easily achieved for RCC, even with full replacement of CA with RCCA. Therefore, the importance of incorporation of the VHT in the mix design process and the possibility of full replacement of CA of RCC by RCCA, are elaborated in this research.
2020-12-01T00:00:00ZStatistical approach to develop high mobility road network plan for Sri LankaWeththasinghe, SBandara, Shttp://dl.lib.uom.lk/handle/123/179862022-06-21T08:47:34Z2020-12-01T00:00:00ZStatistical approach to develop high mobility road network plan for Sri Lanka
Weththasinghe, S; Bandara, S
Perera, HLK
Transportation among major commercial and socio-economic hubs will play a vital role in the economy during the next decade. Therefore, it is essential to look forward to developing a road network with high mobility among major hubs (can be considered as nodes) taking into
account the existing and under construction expressway network.
Since administrative districts and its capitals have already defined, initially nodes to be served are defined as capitals of each district. Population, commercial activities, special
tourist/pilgrims attractions are considered a major trip generating and attracting factors. Transport activity level and the population can be considered as directly proportional to above.
Existing travel time and existing allowable speed or average speed between the nodes are the other essential initial data collected for identification of critical paths to access all nodes. In addition to 25 district capitals, other major road intersections (such as Dambulla) and expressway interchanges were also considered as nodes when defining the initial road network.
During analyzing stage, development of minimum distance paths (which can be used to identify the level of service between two critical nodes) and minimum spanning tree (which is used to identify the most feasible network for the economy) to access all nodes was considered to identify bottlenecks and additional nodes required. Google data and data from other valid sources were used to develop origin-destination matrices with respect to travel time, distance, and vehicular average speed. With the effective use of tools such as SPSS as well as several online tools developed based on Dijkstra's algorithm, minimum distance path and the minimum spanning tree were developed to identify the feasible behaviour of the existing network. Adding new links to the expressway networks and improvements to other main roads are done using network analysis tools. To identify the optimum network, two criteria; minimizing overall link length and achieving desired average speed levels were considered. A logical criterion to be developed to identify the links to be added or improved such that overall mobility level of the country is improved.
Hambanthota, Rathnapura were identified as critical nodes due to influence from expressways
(functioning & proposed). Dambulla was identified as a critical node which influences the mobility of northern and eastern nodes. Nodes and links located in the central region were
identified as bottlenecks of the entire network due to geographical barriers (terrain & landslide issues)
2020-12-01T00:00:00Z