RESUMEN
Developments in the transportation field are emerging because of the growing worldwide demand and upgrading requirements. This study measured the transportation development, shortage distance, and decadal land transformation of Kuala Lumpur and Madrid using various remote sensing and GIS approaches. The kernel density estimation (KDE) tool was applied for road and railway density analysis, and hotspot information increased the knowledge about assessable areas. Landsat datasets were used (1991-2021) for land transformation and related analyses. The built-up land increased by 1327.27 and 404.09 km2 in Kuala Lumpur and Madrid, respectively. In the last thirty years, the temperature increased 6.45 °C in Kuala Lumpur and 4.15 °C in Madrid owing to urban expansion and road construction. Chamberi, Retiro, Moratalaz, Salama, Wangsa Maju, Titiwangsa, Bukit Bintang, and Seputeh have very high road densities. KDE measurements showed that the road densities in Kuala Lumpur (4498.34) and Madrid (9099.15) were high in the central parts of the city, and the railway densities were 348.872 and 2197.87, respectively. The observed P values were 0.99 and 0.96 for traffic signals and 0.98 and 0.99 for bus stops, respectively. The information provided by this study can support local planners, administrators, scientists, and researchers in understanding the global transportation issues that require implementation strategies for ensuring sustainable livelihoods.
RESUMEN
Conventional bitumen pavement is no longer suitable for handling increasing loads and weather variations, which cause road deterioration, Thus, the modification of bitumen has been suggested to counter this issue. This study provides a detailed assessment of various additives for modifying natural rubber-modified bitumen used in road construction. This work will focus on the use of additives with cup lump natural rubber (CLNR), which has recently started to gain attention among researchers, especially in rubber-producing countries such as Malaysia, Thailand and Indonesia. Furthermore, this paper aims to briefly review how the addition of additives or modifiers helps elevate the performance of bitumen by highlighting the significant properties of modified bitumen after the addition of modifiers. Moreover, the amount and method of application of each additive are discussed further to obtain the optimum value for future implementation. On the basis of past studies, this paper will review the utilisation of several types of additives, including polyphosphoric acid, Evotherm, mangosteen powder, trimethyl-quinoline and sulphur, and the application of xylene and toluene to ensure the homogeneity of the rubberised bitumen. Numerous studies were conducted to verify the performance of various types and compositions of additives, particularly in terms of physical and rheological properties. In general, additives enhance the properties of conventional bitumen. Future research should investigate CLNR because studies on its utilisation are limited.