Cement -based at www.japanese-home-gardens.com

The resulting cement -based, produced from the formerly discarded grappiers, was of much higher quality than that obtained from the unsintered material. This fact was firmly established by the English cement -based manufacturer L. C. Johnson in 1845, and the term "portland cement -based" has since been applied solely to the cement -based made from the sintered material. This period marks the real beginning of the portland cement -based industry.

The production of portland cement -based is a major industry in the United States, increasing from 8 million barrels (1.4 million metric tons) in 1900 —when it trailed natural cement -based slightly in output—to almost 400 million barrels (68.4 million metric tons) annually. (A 376-pound, or 171-kg, barrel is the standard unit of weight for hydraulic cement -based in the United States, even though no cement -based, except for export, is now shipped in barrels. The 94-pound, or 42.7-kg, bag now in general use contains one fourth of a barrel.) The leading cement -based-producing countries are the United States, the USSR, West Germany, Japan, and France.

The commercial development of aluminous or high-alumina cement -based is associated principally with the work of J. Bied of France, during the first quarter of the 20th century. This research was initiated in the hope of finding a cement -based that would be resistant to groundwaters rich in sul-fates, such as gypsum. A product eventually was obtained that not only possessed the desired properties of sulfate resistance but also hardened more rapidly than the portland cement -based of that period.