Chapter 9 Materials for construction in deserts

Abstract

Civil engineering constructions of all kinds use large quantities of natural materials ranging from soils and clays through sand, gravel and crushed rock to large blocks of rock, which may be used as armourstone, for shaping into dimension stone, or as cladding, tiles or pavers. Excavation, cuttings and ground preparation associated with many construction projects require large volumes of soil and rock to be removed. Where possible, this bulk material is reused as foundation layers for buildings and roads, and, more commonly, as fill for embankments or bunds. Today, there is increasing pressure to reuse or recycle the demolition waste materials from redundant buildings. Timber is a scarce commodity in desert regions and is usually imported. Consequently, it is often reused or used as a fuel source. However, it is also becoming more common for solid building wastes such as concrete and brick to be recycled as ‘secondary’ aggregate or fills. Natural geological materials of all kinds may be found in desert regions and are described in Chapters 3 and 5. They are similar to materials found in other parts of the world, but the special environmental conditions of deserts (as described in Chapters 2–4) can lead to the alteration of these geological materials to form unique associations of rock, and also to create new ones that are specific to deserts. Where possible, the bulk natural raw materials for construction in deserts are sourced locally, which may imply that less than ideal material will have to be used in some circumstances. The uses of natural materials in construction can be categorized under the following general applications: