Sand and gravel as aggregate

Archer, A.A.. 1972 Sand and gravel as aggregate. London, UK, HMSO, 35pp. (Mineral Dossier No. 4)

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Abstract/Summary

The terms sand and gravel relate to size rather than to composition: many rock types are present in gravels, the most common being flint, limestone, quartzite and igneous rocks. There is more than one definition of the boundary between sand and gravel and there are many specifications for different uses. This dossier is primarily concerned with sand and gravel used as an aggregate or bulking material, in the main for concrete (probably accounting for 75 per cent of total production) and road construction, rather than with the more specialised sands used in glass-making and metal-founding. Sand and gravel are of prime importance to the national economy and are second only to coal in terms of tonnages of minerals produced in this country. Total past production is about 2,500 million tonnes, of which over half has been raised in the last fifteen years, annual production now averaging about 115 million tonnes. After a substantial rise over the last two decades, the rate of increase in production, which has been substantially greater than that of the total output of the construction industry, has declined in recent years. A recent forecast based on NEDO data for the construction industry suggests a demand of 155 million tonnes per annum by 1980. The bulk of production is from superficial deposits, the terrace and river gravels of southern England and the Midlands being particularly important, especially along the Thames and Trent and their tributaries. Glacial and fluvioglacial material assumes a greater importance in northern England. By comparison, only a small amount is won from rocks older than the Pleistocene: the main sources are the Bunter Pebble Beds of the Midlands and the Lower Greensand of south-east England. Outside south-east England and the Midlands crushed rock is a major competitor. The United Kingdom is the world's largest producer of marine-dredged aggregates, which account for 12 per cent of the total output. Of the 13~ million tonnes dredged in 1970, 3.3 million tonnes were landed at foreign ports. The principal dredging grounds lie off the Isle of Wight, off the mouths of the Thames and Humber, in Liverpool Bay and the Bristol Channel. Sand and gravel is won by conventional earthmoving techniques (or by dredging, in wet working) from open pits which may be below (wet) or above (dry) the water table, an average yield being about 20,000 yds3 per acre (about 58,000 tonnes per hectare). It is estimated that about 4,000 acres (1,600 hectares) are worked each year, of which 2,500 acres (1,000 hectares) are accounted for by wet pits. Almost all workings are controlled by planning permissions which are normally subject to conditions which reduce their impact on the environment and ensure that appropriate after-treatment is I undertaken. Old pits have been successfully converted into recreational parks or may be used for building development when filled. In the main, few workings are found in areas of high landscape value, although the pressures on high-grade agricultural land may be great in some of the larger river valleys. Processing involves washing, screening and/or classifying; aggregates are often blended to comply with user specifications. Extensive research is undertaken by the industry and government research establishments into the use of aggregates. Sand and gravel command the lowest price range of all minerals marketed in this country, although it is difficult to arrive at a representative ex-pit price. An average price of sand and gravel from a number of pits in England and Wales was reported to be £0.79 per yd3 (about £1.03 per m3) in 1970; a comparable Scottish price is £0.58~ per yd3 (about £0.77 per m3). Transport costs are usually an important factor in the delivered price. There are about 500 producing companies, most of which only operate one pit, although in 1965 the 17 largest companies accounted for about one third of the total output. Since then, amalgamations have significantly increased the proportion produced by the largest firms.

Item Type:	Publication - Report
Programmes:	BGS Programmes > Economic Minerals
Funders/Sponsors:	Institute of Geological Sciences
Additional Keywords:	Mineral, Sand and gravel
NORA Subject Terms:	Earth Sciences
Date made live:	28 Jul 2025 15:33 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/539895

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