Library builder

Recycled and alternative materials are finding increased use in the construction of road pavements and embankments. Environmental concerns are leading to con­straints on quarrying of the materials that have, conventionally, been used while tax incentives and legislative limitations are encouraging the uptake of wastes, by-products and recycled elements in their place. These materials do not, […]

In the road environment, contaminants are almost entirely moved by water-based or air-based processes. Air-based processes are, principally, by dust and spray, but these are not discussed further, being beyond the scope of this book. In water — based processes, contaminants are carried in and/or by the water through soil or aggregate pores, over the […]

The upper, bound layers in a pavement are little affected by pavement moisture. “Stripping” can occur in repeated wet weather when the traffic loading causes pulses of pressure of water which has seeped into cracks in the bound materials. Exploiting micro-cracks this water can separate the binder from the aggregate it is supposed to bind, […]

It is conventional to classify pavements according to their construction — flexible (i. e. principally made of asphalt or only granular), rigid (i. e. concrete) and semi-rigid (i. e. made of both concrete and asphalt layers). From the point of view of water movements these classifications are not very relevant. Instead, pavements may be classified […]

Modern pavements normally comprise one or more bound layers overlying one or more unbound aggregate layers which, in turn, rest on the subgrade. In almost all cases the uppermost layers are bound by bitumen or cement. In the case of an embankment the subgrade is comprised of imported fill. In the case of a cutting […]

1.4.1 Definitions In today’s world almost all traffic runs on an improved surface and not on the nat­ural soil profile… and most users give such improved surfaces little thought. This improved surface is known as a pavement and may be a simple layer of imported aggregate or the structure that comprises a modern expressway. In […]

The book covers both theory and practice and addresses both sub-surface drainage and water quality issues. Chapter 2 deals with basic flow and suction theory and Chapter 4 with heat transfer, which is implicated in driving water movement by phase change mechanisms (freezing, thawing, evaporation). Chapter 6 establishes a basis for discussing environmental aspects, introducing […]

The main aim of this book is to increase the knowledge about water in the sub­surface road environment so as to improve highway performance and minimise the leaching of contaminants from roads. Improvement of pavement performance will lead to less road closures, better use of the road network, longer service life and more effective transportation […]

In Europe road construction may date back as far as 3,500 years ago. These early roads were probably largely for ceremonial purposes, over short distances, and may have carried little, if any, wheeled traffic. It was not until the growth of the Ro­man Empire that a large network of engineered pavements was first constructed (Fig. […]

The following have contributed to this book. Where a name is shown in bold, he or she is a contributor to one of the main chapters. Where a name is shown in bold and italics, the person was a contributor to one of the main chapters but not a member of the COST 351 project. […]