Clay, noun. Old English Claég. A stiff viscous earth. (Blackies Compact Etymological Dictionary. Blackie & Son, London and Glasgow. 1946. War Economy Standard)
Clay: The original Indo-European word was ‘gloi-’, ‘gli-’ from which came ‘glue’ and ‘gluten’. In Germanic this became ‘klai’, and the Old English ‘claeg’ became Modern English ‘clay’. From the same source came ‘clammy’ and the northern England dialect ‘claggy’ all of which describe a similar sticky consistency. (Oxford English Dictionary and Ayto’s Dictionary of Word Origins, Bloomsbury, 1999)
Clay: from Old Greek γλi;α, γλοi;α “glue”, γλi;υή “slime, mucus”, γλοi;ός “anything sticky” from I.-E. base *glei-, *gli- ‘to glue, paste stick together (Klein E. A comprehensive etymological dictionary of the English language. Elsevier, Amsterdam, 1967; Skeat W. An etymological dictionary of the English language. Oxford University Press, 1961; Mann S.E. An Indo-European comparative dictionary, Buske Verlag, Hamburg, 1987)
Definitions of clay are given in Section 1.2. The uses of clay are ubiquitous and diverse. On a world scale, clay is of major economic significance, touching virtually every aspect of our everyday lives, from medicines to cosmetics and from paper to cups and saucers. It is very difficult to over-estimate its use and importance. The treatment of clay in this book is therefore wide ranging to reflect this situation.
The occurrence of clay is also ubiquitous and diverse (see Text Box below) and, with its various mineral species, properties and behavioural characteristics, the industrial applications of clay are thus manifold and complex. As well as their traditional major uses for brickmaking, pottery and porcelain manufacture, refractories and the fulling of cloth, clays are now used for refining edible oils, fats and hydrocarbon oils, in oil well drilling and synthetic moulding sands, in the manufacture of emulsified products in paper and, as noted in Chapters 13, 14 and 15, many hundreds of other uses, including medicine, cosmetics and, on a larger scale, as fillers, as well as many uses in geotechnical engineering e.g. for grouts, membranes etc.
Figures & Tables
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.