Development of an Empirical-Mechanistic Model of Overlay Crack Progression using Data from the Washington State PMS Database

This is the second of two reports that present fatigue cracking performance models for asphalt concrete overlays placed on existing asphalt concrete pavement. The models were developed from the pavement management system (PMS) database of the Washington State Department of Transportation (WSDOT). The database included existing pavement structure, overlay thickness and type, truck traffic, and observed percent of the wheelpath cracked from annual condition surveys. Climate data was developed by the UCPRC to augment the WSDOT data. This report presents a model for crack propagation, starting from crack initiation, which was defined as 5 percent of the wheelpath with longitudinal cracking. The combined initiation and propagation models were included in a spreadsheet calculator which was used to perform an analysis of the sensitivity of crack initiation and propagation to the input variables. The models are extremely useful for predicting pavement performance. For use in California they will need recalibration of the coefficients to reflect differences in WSDOT and California practice, primarily the use of thicker overlays in California, placement of overlays at much more advanced states of cracking in the existing pavement, and possible differences in routine maintenance activities

Development of an Empirical-Mechanistic Model of Overlay Crack Progression using Data from the Washington State PMS Database

This is the second of two reports that present fatigue cracking performance models for asphalt concrete overlays placed on existing asphalt concrete pavement. The models were developed from the pavement management system (PMS) database of the Washington State Department of Transportation (WSDOT). The database included existing pavement structure, overlay thickness and type, truck traffic, and observed percent of the wheelpath cracked from annual condition surveys. Climate data was developed by the UCPRC to augment the WSDOT data. This report presents a model for crack propagation, starting from crack initiation, which was defined as 5 percent of the wheelpath with longitudinal cracking. The combined initiation and propagation models were included in a spreadsheet calculator which was used to perform an analysis of the sensitivity of crack initiation and propagation to the input variables. The models are extremely useful for predicting pavement performance. For use in California they will need recalibration of the coefficients to reflect differences in WSDOT and California practice, primarily the use of thicker overlays in California, placement of overlays at much more advanced states of cracking in the existing pavement, and possible differences in routine maintenance activities

The Built Environment: Cities, Water Systems, Energy, and Transport

The climate is changing, and the Eastern Europe and Central Asia (ECA) region is vulnerable to the consequences. Many of the region's countries are facing warmer temperatures, a changing hydrology, and more extremes, droughts, floods, heat waves, windstorms, and forest fires. This book presents an overview of what adaptation to climate change might mean for Eastern Europe and Central Asia. It starts with a discussion of emerging best-practice adaptation planning around the world and a review of the latest climate projections. It then discusses possible actions to improve resilience organized around impacts on health, natural resources (water, biodiversity, and the coastal environment), the 'unbuilt' environment (agriculture and forestry), and the built environment (infrastructure and housing). The last chapter concludes with a discussion of two areas in great need of strengthening given the changing climate: disaster preparedness and hydro-meteorological services. This book has four key messages: a) contrary to popular perception, Eastern Europe and Central Asia face significant threats from climate change, with a number of the most serious risks already in evidence; b) vulnerability over the next 10 to 20 years is likely to be dominated by socioeconomic factors and legacy issues; c) even countries and sectors that stand to benefit from climate change are poorly positioned to do so; and d) the next decade offers a window of opportunity for ECA countries to make their development more resilient to climate change while reaping numerous co-benefits