Mokoena, RefiloeMturi, George AJMaritz, JohanMateyisi, MohauKlein, Pieter2022-03-292022-03-292022-01Mokoena, R., Mturi, G.A., Maritz, J., Mateyisi, M. & Klein, P. 2022. African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection. <i>Sustainability, 14(3).</i> http://hdl.handle.net/10204/123542071-1050https://doi.org/10.3390/su14031048http://hdl.handle.net/10204/12354The reliable performance of roads is crucial for service delivery, and it is a catalyst for domestic and cross-border spatial development. Paved national roads are expected to carry higher traffic volumes over time as a result of urbanization and to support the economic development in the continent. Increased traffic levels combined with expected increases in air temperatures as a result of global warming highlight the need to appropriately select bituminous road materials for a reliable performance of asphalt roads. The objective of the paper is to present African case studies on the development of temperature maps necessary for performance-graded bitumen selection for road design and construction. A consistent approach, that caters for the variability of geographical, environmental and climatic conditions, does not currently exist within the continent. Therefore, this paper discusses a series of critical components in the development of temperature maps for performance-graded bitumen including (i) pavement temperature models and climatic zones in Africa; (ii) the effect of urban heat islands on pavement temperature; (iii) sources of weather data and (iv) the mapping procedure to produce temperature maps. Characterizing the thermal properties of the pavement was found to be an important factor for reliably calculating expected road temperatures as well as the consideration of the ambient climate for a given location. During this study, the urban heat island effect was found to have little influence on the maximum pavement temperatures but a significant effect on the minimum pavement temperatures. Some areas of the urban district assessed in this investigation were found to increase by two performance grades according to the minimum temperature criteria. The recent observed weather data from weather stations are the most accurate means of measurement of the ambient environmental conditions necessary for performance-based specifications, but they are not always easily accessible, and therefore other sources of data, such as satellite data, may need to be used instead. With the expected temperature increases expected as a result of climate change, the use of Global Climate Models also opens new avenues for performance-based material selection in the African continent for expected climates as an alternative to traditional approaches based on historically observed weather.FulltextenAsphalt pavement temperaturesBitumen selectionPerformance-graded bitumenTemperature mapsArticleMokoena, R., Mturi, G. A., Maritz, J., Mateyisi, M., & Klein, P. (2022). African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection. <i>Sustainability, 14(3)</i>, http://hdl.handle.net/10204/12354Mokoena, Refiloe, George AJ Mturi, Johan Maritz, Mohau Mateyisi, and Pieter Klein "African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection." <i>Sustainability, 14(3)</i> (2022) http://hdl.handle.net/10204/12354Mokoena R, Mturi GA, Maritz J, Mateyisi M, Klein P. African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection. Sustainability, 14(3). 2022; http://hdl.handle.net/10204/12354.TY - Article AU - Mokoena, Refiloe AU - Mturi, George AJ AU - Maritz, Johan AU - Mateyisi, Mohau AU - Klein, Pieter AB - The reliable performance of roads is crucial for service delivery, and it is a catalyst for domestic and cross-border spatial development. Paved national roads are expected to carry higher traffic volumes over time as a result of urbanization and to support the economic development in the continent. Increased traffic levels combined with expected increases in air temperatures as a result of global warming highlight the need to appropriately select bituminous road materials for a reliable performance of asphalt roads. The objective of the paper is to present African case studies on the development of temperature maps necessary for performance-graded bitumen selection for road design and construction. A consistent approach, that caters for the variability of geographical, environmental and climatic conditions, does not currently exist within the continent. Therefore, this paper discusses a series of critical components in the development of temperature maps for performance-graded bitumen including (i) pavement temperature models and climatic zones in Africa; (ii) the effect of urban heat islands on pavement temperature; (iii) sources of weather data and (iv) the mapping procedure to produce temperature maps. Characterizing the thermal properties of the pavement was found to be an important factor for reliably calculating expected road temperatures as well as the consideration of the ambient climate for a given location. During this study, the urban heat island effect was found to have little influence on the maximum pavement temperatures but a significant effect on the minimum pavement temperatures. Some areas of the urban district assessed in this investigation were found to increase by two performance grades according to the minimum temperature criteria. The recent observed weather data from weather stations are the most accurate means of measurement of the ambient environmental conditions necessary for performance-based specifications, but they are not always easily accessible, and therefore other sources of data, such as satellite data, may need to be used instead. With the expected temperature increases expected as a result of climate change, the use of Global Climate Models also opens new avenues for performance-based material selection in the African continent for expected climates as an alternative to traditional approaches based on historically observed weather. DA - 2022-01 DB - ResearchSpace DP - CSIR J1 - Sustainability, 14(3) KW - Asphalt pavement temperatures KW - Bitumen selection KW - Performance-graded bitumen KW - Temperature maps LK - https://researchspace.csir.co.za PY - 2022 SM - 2071-1050 T1 - African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection TI - African case studies: Developing pavement temperature maps for performance-graded asphalt bitumen selection UR - http://hdl.handle.net/10204/12354 ER -25428