Evaluating potential of diatomite as anti clogging agent for porous asphalt mixture

Clogging is a major problem that occurs throughout the service life of porous asphalt due to the open nature of the mixture itself. Diatomite with characteristic of abrasiveness and porous structure seems to have potential in order to remove the clogging materials that mainly consists of soils. This study aims to investigate the effects of diatomite as anti-clogging agent on the permeability rate and strength of porous asphalt. The porous asphalt samples were prepared using Malaysia aggregate gradation and polymer modified bitumen of PG76 was used as the binder. This study focuses on clay as the clogging material at different concentration. A fixed amount of 0.5 g/L diatomite was applied to the porous asphalt samples as an anti-clogging agent prior to clogging cycles. The permeability test and resilient modulus were then conducted at different clogging concentrations (0.5, 1.0, 1.5 g/L) and cycles, with and without diatomite. It was found that samples with diatomite have a higher permeability rate compared to those without any application of diatomite after a few clogging cycles. As the clogging cycles increase, the clogging materials have trapped and filled up the voids in the porous asphalt samples and increase the resilient modulus result

Correlation between functional and structural properties of flexible pavement

The functional properties and structural properties are very important in order to evaluate and determine the pavements performance. In pavement condition assessment, monitoring and measurement on the functional and structural properties of the pavement are really needed in order to determine the remaining life of the pavement before any rehabilitation work can be done. This study had further looked on the correlations between these functional and structural properties on a flexible pavement. The study had collected 1198 numbers of functional properties data namely International Roughness Index (IRI), rut depth and texture depth. While for structural properties, 120 numbers of elastic modulus and 12 numbers of California Bearing Ratio (CBR) data has been measured. The functional properties were measured by using Multi Laser Profiler (MLP), while the structural properties were collected by using Falling Weight Deflectometer (FWD) and Dynamic Cone Penetrometer (DCP). The data collection was done along 60 km of asphalt pavement road. Regression analysis shows that the coefficient of determination, R2 obtained for all parameter is near to 0. These results generally conclude that there are no correlations between the functional properties and structural properties on a flexible pavement

Brasília and Putrajaya: Using urban morphology to represent identity and power in national capitals

Brasília, the national capital of Brazil, and Putrajaya, the new administrative capital of Malaysia, were created generations apart and on different continents. Brasília was created as an icon of Modernist architecture, while Putrajaya represents the emergence of new symbolic relationships between government and economic prowess. Like most new towns built in the twentieth century, they were made possible by government backing. This paper explores the ideological basis for the production of urban space in the development of seats of national governments. The analysis of Brasília and Putrajaya confirms that governments use urban design in national capitals to represent power