Browsing by Author "De Silva, MSK"

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item: Thesis-Abstract
Applicability of steel fibers to improve the properties of cement stabilized...
(2015-09-16) De Silva, MSK; Mampearachchi WK
Stabilized bases are normally designed for the heavy traffic categories or in the absence of base materials which should have the required material properties according to the specifications so that the higher strength category can be achieved. Bases can be constructed using soil or aggregates. Those are stabilized with various admixtures such as lime, sand or cement. Among them, cement stabilization is a common practice in road construction industry. The road construction industry has the experiences about the stabilization of dense graded aggregate bases with cement. Even though the content of cement has to be increased to get the higher strength capacity, shrinkage cracks may appear with the increase usage of the cement content and it has a tendency to convert the layer to a rigid pavement too. Hence, another feasible technique should be applied to achieve the required higher strength capacities concurrently to diminish shrinkage cracks and form the base withstand against higher number of heavy load repetitions as well as form the base withstand against higher number of heavy load repetitions without converting the layer into rigid. To achieve both phenomena, this research was carried out to introduce usage of a reinforcement type such as steel fibers in Dense Graded Aggregate bases. In this study, it is discussed about the high performance of Steel Fiber Reinforced Cement Stabilized bases over the conventional Cement Stabilized Bases. Based on the results, a Pavement Design Chart was developed for Steel Fiber Reinforced Cement Stabilized Bases suitable for higher Traffic Classes such as T7 and T8. This can be used in general practice without doing any calculations.
item: Conference-Abstract
Effectiveness of rolling straight edge for quality control of asphalt concrete surfacing
(Department of Civil Engineering, University of Moratuwa., 2011-07) De Silva, MSK; Mampearachchi, WK; Pasindu, HR
Today in each part of the country, road surfacing is done by Asphalt Concrete. With the increase usage of Asphalt Concrete, the necessity of Quality Management System was arisen. Hence the Quality Management System for Asphalt Pavement was developed and established in following areas; 1. Plant operation 2. Asphalt Concrete transportation 3. Paving and Compaction 4. On finished Asphalt pavement To check the quality control on finished pavement, there are many parameters to be considered. One important parameter is Roughness value on the finished pavement. Different Technical Specifications provides various devices to quantify the Roughness value. One such method is to measure Roughness value using the Rolling Straight Edge. Here the dominant parameter is ups and downs of the road surface. Rolling Straight Edge equipment was used to count total ups and downs (Bumps) with magnitude of a particular length. A correlation between International Roughness Index and Rolling Straight Edge measurement has been developed using statistical analysis software SPSS. Most significant parameters for the roughness were identified and modifications to the specification were made. IRI = 1.662 + 0.02X; (X = Summation of the magnitude of the total bumps >=4mm) A case study on identifying the high roughness sections of a road was made and effects of remedial measures were analyzed using the developed correlation.