Ever since man began establishing settlements in prehistoric times, he has been reshaping his built environment. The placement of clay has been used to form embankments, dams, quarry tips, mounds or levelled areas. This process is referred to as ‘filling’ and the final structure is known as a ‘fill’. By excavating clays, engineering structures such as cuttings, ditches and moats have been constructed. Clay has also been excavated as a raw material in manufacturing, for example for the pottery and building industries. The resulting fill structures and excavations are collectively referred to as earthworks. Horner (1988) and Trenter (2001) provide a thorough summary of British practice and the somewhat dated ‘Earth Manual’ (US Bureau of Reclamation 1974) describes American practice. A particular useful reference on the use of soil and rock in construction with an emphasis on Australian experience is given by McNally (1998) and Fookes (1997) covers tropical residual clay soils in terms of characteristics, description and engineering properties.
It is likely that the earliest earthworks were for the purpose of living and defence but as populations increased water supply and irrigation became important. Although many of the earliest earthworks have become obscured with time, canals have been dated from about 4000 BC in Iran and earth dams in Jordan from about 3200 BC (McFarlan 1989). Clays have been excavated for the production of pottery for thousands of years and the occurrence of kaolin-rich clays probably led to the development of porcelain in China.
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Clay Materials Used in Construction
Concluding the trilogy on geological materials in construction by specially convened Geological Society working parties, this authoritative volume reviews many uses of clays, ranginf from simple fills to manufactured products. Comprehensive and international coverage is achieved by an expert team, including geologists, engineers and architects, who met over six years to produce the book. Packed with information prepared for a wide readership, this unique handbook is also copiously illustrated. The volume is dedicated to the memory of Professor Sir Alec Skempton.
Various definitions of ‘clay’ are explored. Clay mineralogy is described, plust the geological formation of clay deposits and their fundamental materials properties. World and British clay deposits are reviewed. New compositional data are provided for clay informations throughout the British stratigraphic column. Investigate techniques and interpretation are considered, ranging from site exploration to laboratory asessment of composition and engineering performance.
Major civil engineering applications are addressed, including earthworks, earthmoving and specialized roles utilizing clays. Traditional earthen building is included and shown to dominate construction in places. Clay-based construction materials are detailed, including bricks, ceramics and cements. The volume also includes a comprehensive glossary.