Portland cement world production

Portland cement is the most widely used constmction material in the world (see Cement), especially in Third World nations, because of its availabiHty, ease of use, and versatiHty. Estimated 1989 worldwide production is almost 1.12 biUion metric tons. The United States represented 71.2 million metric tons, ie, fourth, behind China (207 million metric tons), the former USSR (140 million metric tons), and Japan (82 million metric tons). Spain is tenth with 27 million tons. The top 10 world producers of Portland cement account for just under 43% of the total production. 

Portland cement, a complex mixture of calcium silicates, aluminates, and ferrates, is one of the world s most important construction materials, with annual worldwide production in excess of lO kg. When mixed with water and sand, it changes by slow hydration to concrete. Water and hydroxide link the other components into larger crystals with great strength. 

CACs were developed in response to the need for cements resistant to groundwater and seawater attack and are the only cements, other than Portland cement, that are in continuous long-term production [2], The property of CAC that was most important in their commercial development is the resistance to sulfate attack, which contrasted with the poor-sulfate resistance of contemporary Portland cements [2], and CAC was first patented in 1908 [2], Most early applications, in construction projects following the First World War, were in structures exposed to seawater, such as harbor pilings. Because CAC hardens rapidly, it was adopted for prestressed concrete beams in the post World War II construction boom, with some unfortunate results. Poor understanding of the material properties of CAC and incorrect water to cement ratios led to the collapse of several buildings, and the use of Portland cements, which are cheaper, has replaced CAC in prestressed concrete beams[2]. 

In many countries, cement production represents the second largest outlet for limestone and is exceeded only by the use of limestone for aggregate in construction and building. The world production of Portland cement is in the order of 1420 million tonnes per year [9.1]. The amount of limestone required varies with the grade of cement and the raw materials used, but is estimated to be approximately 1.0 tonne per tonne of cement. Thus the global cement industry uses roughly 1,400 million tonnes per year of limestone, or about 32 % of the extracted limestone. 

The development of calcium aluminate cement was spurred by efforts to overcome the problems associated with sulfate attack on Portland cement based concrete used in the construction of railway tunnels in gypsiferous grounds. The first patent relating to this type of binder was filed in 1908 by Bied in France. The cement was introdueed into production in 1913, and became known as Ciment Fondu. After it was recognized that calcium aluminate cement gains strength much faster than Portland cement, the binder was used in World War I by the French military in the constraction of gun emplacements and shelters, where this property was of paramount importance. After the war, the cement became widely used in other structural applications however, its use in this area became limited, after failures of structures built with this cement were reported from different countries. Nowadays calcium aluminate cement is being used in a variety of special applications. 

Building materials are important man-made structural materials in modern civilization. Today concrete is the most widely used structural material in the world. Actually, the world annual production capacity reaches ca. 1.56 bilhon tonnes of Portland cement which is converted into 11.5 bilhon tonnes of concrete, that is, concrete with reinforced steel bars or rebars. Despite that fact that concrete is considerably weaker than steel, it is preferred because ... 

The progress in the cement industry is directed towards very low exhaustion of deleterious gases and powders, reduction of energy required and use of supplementary fuel materials, such as used tyres, etc. The majority of cement production in the world concerns blended Portland cement with various... 

Table 17.1 The World and US production of Portland cement—million metric tons ...

FIG. 4—Rise and decline of Roman cements in continental Europe by the example of amounts of cement delivered in the Austro-Hungarian Empire from the start of cement production until the end of World War I. RC =Roman cement, PC =Portland cement. Figures compiled from [24],... 

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