Reuse of materials in coastal and river engineering

Abstract

The increased demand for materials for flood and coastal defences as sea levels rise and rainfall increases should be reflected by a sustainable use of natural resources. Recycled and secondary materials offer significant potential to reduce the demand for primary materials, but the way in which this is done in a sensitive water environment will be of interest to the whole of the construction industry. The paper examines five criteria that should influence choices between materials options for projects: whole-life costs, technical efficacy, impact on the local environment, environmental impact of materials production and procurement policy. The latter is examined in the context of the sensitivity of the procurement of tropical hardwoods, which are in particular demand because of their durability. A case example is given of the reconstruction of the fire-damaged Southend Pier in which reclaimed tropical hardwoods were imported from the Netherlands for most of the work. Finally, two examples of the reuse of tyres in baled form are examined. One example looks at the technical advantages of using these recycled materials in a flood embankment project and the other at a pilot project to examine and try to allay concerns about leachates from the tyre material.