Logo Picture Left SideLogo Picture Right SideLogo Text at Center
Home > Search > Site Map > California > The California Stone Industry > California Structural and Industrial Materials / Building Stones

California Structural and Industrial Materials / Building Stones
(historical account leading up to circa 1906 - continued)

The Portland Cement Industry of California:

"Cement, as used in building operations, signifies a compound of lime and other substances that hardens under water or in contact with water. It is a mixture of lime, or lime and magnesia, with clay or silica, or both. It differs from common quicklime in that it does not slake, expand, crumble, nor give off heat when wet, but chemically combines with part of the water into a firm, solid rock. There are two principal classes of cement: the natural rock, or Rosendale cement; and the artificial product, or Portland cement; to which may be added a third, the Pozzolana, or slag cement.

Natural Rock Cement:

"A limestone which in nature contains sufficient clay or other substance, mixed with the carbonate of lime, that it only requires proper burning and grinding to form a cement, is called a waterlime or natural cement rock, and the product is natural or Rosendale cement, sometimes called Roman cement. Natural cement rock was discovered accidentally in the United States in 1818, near Chittenango, N. Y. Later it was found in large quantities in Pennsylvania, Indiana, Kentucky, and elsewhere. Ulster County, New York, and Louisville, Kentucky have always been the centers of this important industry. The natural cement is generally inferior to the Portland cement, and in some places, especially in a few localities in New York State, its market is being gradually taken by the artificial product.

"The only natural cement rock known in this State comes from Orange County, where a body of it, claimed to be of good quality, is found.

Portland Cement:

"Portland cement may be defined as a compound consisting chiefly of silicates and aluminates of lime, produced by the calcination to incipient vitrification of a mechanical mixture of calcareous and argillaceous materials, the clinker thus produced being subsequently ground to a more or less impalpable powder. The exact chemical composition of Portland cement varies considerably; its principal constituents are lime, silica, alumina, and oxide of iron, which are found, roughly, in the following proportions: lime, 60 to 64 per cent; silica, 20 to 24 per cent; alumina, 6 to 10 per cent; iron oxide, 3 to 5 per cent. These four constituents, as a rule, amount to about 96 per cent, the remainder consisting of small quantities of sulphuric anhydride, magnesia, alkalies, etc. (See Portland Cement, D. B. Butler, page 10. Geological Survey of Ohio (4th series), Bulletin No. 3, The Manufacture of Hydraulic Cements, by A. V. Bleininger. A paper by same writer in the transaction of the American Ceramic Society, 1903. Chemical and Engineering News, 1898, Vol. IV, page 5, etc.) The use of Portland cement is principally based on its characteristic quality to harden rapidly under water or in a moist atmosphere.

"Portland cement was first manufactured and so named in 1824 by Joseph Asdin,* who took out a patent for it as 'an improvement in the modes of producing an artificial stone.' The growth of the industry was very slow at first. It was not until 1851 that it was first brought prominently before the world, and soon after its manufacture began in Germany, France, and elsewhere on the continent. The increase in the output was rapid from this time, especially in Germany and England, both of which countries exported large quantities to the United States.

"In the United States the first Portland cement was manufactured in 1875, by Mr. Saylor, at Siegfriend, in eastern Pennsylvania. A second factory was soon afterwards established in western Pennsylvania. For nearly twenty years the growth of the industry was very slow indeed, but during the last decade of the nineteenth century there was a phenomenal increase in the product. This was brought about by the greatly increased use of cement, which without any marked decrease in importation raised the home production in one decade more than 1200 per cent...."

(* Footnote: While Aspdin is usually credited with inventing the Portland cement, it is thought that he originated the name only, as the cement which he made was a Rosendale or Roman cement, and not a Portland cement.)

Portland Cement Factories in California:

"At present (1904) there are three cement factories in operation in California, located at Napa Junction, Napa County; at Colton, San Bernardino County; and at Cement, near Suisun, Solano County. At other places cement works are projected in the near future. The oldest factory is that at Colton. The one at Suisun began in 1902, and the one at Napa Junction in 1903."

California Soapstone - Talc:

"Talc is a hydrous silicate of magnesia (4 MgO, 5 SiO2, H2O) that occurs in different varieties, of which soapstone is one of the most important.

"Soapstone is a harder, more compact variety, and is used in the manufacture of many articles such as bath and laundry tubs, firebacks for stoves, hearthstones, mantels, sinks, griddles, slate pencils, gas tips, switchboards for electric plants, and other articles.

"Talc is used as powder, or flour talc, and as pieces saws into various sizes and shapes. the flour talc is used in fireproof paints, lubricants, many of the cheaper soaps, electric insulators, boiler and steampipe covers, foundry facings, for the dressing of skins, and in the manufacture of dynamite, toilet powder, and paper. (See Bureau of Census, Mines and Quarries, 1903, p. 1065.)"

Portland Cement Industry in California (circa 1906).

“Cement, as used in building operations, signifies a compound of lime and other substances that hardens under water or in contact with water. It is a mixture of lime, or lime and magnesia, with clay or silica, or both. It differs from common quicklime in that it does not slake, expand, crumble, nor give off heat when wet, but chemically combines with part of the water into a firm, solid rock. There are two principal classes of cement: the natural rock, or Rosendale cement; and the artificial product, or Portland cement; to which may be added a third, the Pozzolana, or slag cement.

Natural Rock Cement.

“A limestone which in nature contains sufficient clay or other substance, mixed with the carbonate of lime, that it only requires proper burning and grinding to form a cement, is called a waterlime or natural cement rock, and the product is natural or Rosendale cement, sometimes called Roman cement. Natural cement rock was discovered accidentally in the United States in 1818, near Chittenango, N. Y. Later it was found in large quantities in Pennsylvania, Indiana, Kentucky, and elsewhere. Ulster County, New York, and Louisiana, Kentucky, have always been the centers of this important industry. The natural cement is generally inferior to the Portland cement, and in some places, especially in a few localities in New York State, its market is gradually taken by the artificial product.

“The only natural cement rock known in this State comes from Orange County, where a body of it, claimed to be of good quality, is found.

Portland Cement.

“Portland cement may be defined as a compound consisting chiefly of silicates and aluminates of lime, produced by the calcinations to incipient vitrification of a mechanical mixture of calcareous and argillaceous materials, the clinker thus produced being subsequently ground to a more or less impalpable powder. The exact chemical composition of Portland cement varies considerably; its principal constituents are lime, silica, alumina, and oxide of iron, which are found, roughly in the following proportions: lime, 60 to 64 per cent; silica, 20 to 24 per cent; alumina, 6 to 10 per cent; iron oxide, 3 to 5 per cent. These four constituents, as a rule, amount to about 96 per cent, the remainder consisting of small quantities of sulphuric anhydride, magnesia, alkalies, etc. (See Portland Cement, D. B. Butler, page 10. Geological Survey of Ohio (4 th series), Bulletin No. 3, The Manufacture of Hydraulic Cements, by A. V. Bleininger. A paper by same writer in the Transactions of the American Ceramic Society, 1903. Chemical and Engineering News, 1898, Vol. IV, page 5, etc.) The use of Portland cement is principally based on its characteristic quality to harden rapidly under water or in a moist atmosphere.

“Portland cement was first manufactured and so named in 1824 by Joseph Aspdin,* who took out a patent for it as ‘an improvement in the modes of producing an artificial stone.’ The growth of the industry was very slow at first. It was not until 1851 that it was first brought prominently before the world, and soon after its manufacture began in Germany, France, and elsewhere on the continent. The increase in the output was rapid from this time, especially in Germany and England, both of which countries exported large quantities to the United States .

(* While Aspdin is usually credited with inventing the Portland cement, it is thought that he originated the name only, as the cement which he made was a Rosendale or Roman cement, and not a Portland cement.)

“In the United States the first Portland cement was manufactured in 1875, by Mr. Saylor, at Siegfried, in eastern Pennsylvania . A second factory was soon afterwards established in western Pennsylvania . For nearly twenty years the growth of the industry was very slow indeed, but during the last decade of the nineteenth century there was a phenomenal increase in the product. This was brought about by the greatly increased use of cement, which without any marked decrease in importation raised the home production in one decade more than 1200 per cent. The following figures indicate the great increase in the domestic production and the growing commercial importance of the industry:

Domestic Production, Imports and Exports of Portland Cement,1890-1903

“The enormous increase in the domestic production of Portland cement is a matter of surprise, and yet when one looks at the varied uses to which it is put and the many other places where it might be used, it will be a matter of great surprise if the increased rate of production does not continue for many years.

Uses of Portland Cement. - Because of the ease with which it can be molded or put into desired shapes, its hardness and durability when placed, and its resistance to the action of moisture and vermin, Portland cement will continue to increase in importance in structural and engineering work. It is not only replacing the ordinary lime mortar in masonry, especially in foundations, but is even replacing stone and brick, and for many uses wood and iron, in the structures.

“Cement is used both in the manufacture of artificial stone, and in concrete, which material is much used for monolithic structures, in walls (e. g. the Museum of Fine Arts at the Stanford University), foundations, bridge construction (e.g. the bridge of the Salt Lake Railway at Riverside), reservoir dams, etc.

“The following list, arranged alphabetically, indicates the more important present uses of Portland cement: abutments, arched culverts, artistic tile, artificial stone, bank vaults, breakwaters, concrete in many places, curbs and gutters, dams and wheel-pits, dry docks, engine beds, fence posts, fireproof floors, etc., fortifications, foundations and walls, foundations for brick and asphalt pavements, irrigation flumes, linings of war vessels, locks of canals, pavements, piers, piling, pipe mains, railway ties, reservoirs, retaining walls and embankments, sea walls, sewers, shingles, stucco, telephone conduits, terra cotta blocks, tombstones, tunnel linings, and burial tombs. The list is capable of indefinite extension, as possibly no other modern product commends itself so readily to so many different uses.

Ill. No. 78. Santa Ana Viaduct, on the S. P., L. A. & S. L. R. R., Crossing Santa Ana River, near Riverside. Santa Ana Viaduct

“The quantity of Portland cement used in California is far in excess of that manufactured in the State. With large deposits of limestone and clay quite widely scattered over the State, and a large fuel supply, it would seem as though the cement industry ought to increase quite rapidly. The State should be exporting rather than importing cement. For many years the development of the cement industry, like many other manufacturing industries in California, was hindered by the high price of fuel, but with the opening of the great oil fields this difficulty has been overcome.

Tests of Portland Cement. - The tests recommended by the American Society of Civil Engineers for Portland cement are: (1) For fineness - Cement shall be ground to such fineness that 95 per cent by weight will pass through a standard sieve of 50 meshes per inch (2500 meshes per square inch), and 90 per cent will pass through a standard sieve of 100 meshes. (2) For soundness - The cement shall endure the hot water test at 25° F. for twenty-four hours without cracking or blowing. (3) For initial set - Neat cement shall not set to support ¼ pound on ½-inch wire in less than fifteen minutes for natural cement, and twenty-five minutes for Portland. (4) For tensile strength - Portland cement briquettes of neat cement mixed three minutes, put in molds with thumbs and trowel, and kept at a temperature of 65° to 70° for one day in moist air and six days in water, shall show a least average tensile strength of 400 pounds per square inch. Briquettes of three parts by weight of standard crushed quartz and one part by weight of Portland cement, mixed in same manner and kept seven days under same conditions, shall show a least average tensile strength of 125 pounds per square inch. Briquettes like the last, kept twenty-eight days under the same conditions, shall show a least average tensile strength of 220 pounds per square inch. (5) For tensile strength, American natural cement - Briquettes of neat natural cement, mixed three minutes, put in molds with thumbs and trowel, and kept at a temperature of 65° to 70° for two hours in moist air and twenty-two hours under water, shall show a least average tensile strength of 60 pounds per square inch. Briquettes of natural cement and standard crushed quartz in equal parts by weight, mixed and handled in the same manner and kept at same temperature for one day in moist air and six days in water, shall show a least average tensile strength of 65 pounds per square inch. briquettes similar to last, and kept twenty-eight days under same conditions, shall show a least average tensile strength of 150 pounds per square inch.

“The standard crushed quartz used in the tests shall pass a sieve of 20 meshes per inch, and shall stop on one of 30 meshes.

“Portland cement is to a great extent bought on the reputation of the brand, hence the importance to the manufacturer of keeping up the regularity of quality of his product.

The Composition of Portland Cement is already given above. The varying amounts of the different constituents influence the character of the cement to a certain extent. Cements rich in lime set more slowly, but harden better than those poor in lime. Cements rich in silica set more slowly than those rich in alumina, but they are better for use under salt water.

“In addition of 0.33 to 0.75 per cent of fluorspar is helpful in making the materials clinker more easily.

“Gypsum or sulphate of lime in small quantities delays the setting of the cement somewhat, and adds to its final strength. More than 4 or 5 per cent is injurious, and many specifications require that less than 2 per cent be added.

“In this country limestone, marl, chalk, and travertine are used in making Portland cement.

Analyses of Raw Materials and the Cement , Colton, California

(*Annual report of State Geologist of New York, 1900, p.24.)

Manufacture of Portland Cement.

“The successive steps in the process of manufacture are the preparation of the raw materials, the mixing, burning, grinding and bolting.

Mixing. - There are two general methods of preparing and mixing the raw materials. One is known as the wet process, and the other as the dry or semi-wet process.

“In the wet process, the mixing is done in water. Sometimes it is necessary to grind the materials first, but as this method is commonly used with chalk or marl, the preliminary grinding is often unnecessary. The mixing is done in large tanks resembling the plungers used in clay-washing plants. In the center of the tank is a vertical rotating shaft, carrying a framework with scrapers, that keeps the materials constantly agitated. Water is let in continually during the mixing, and as it flows out it carries the materials as sediment to the settling tanks, where after the settling of the solids the clear water is drawn off. One of the objections to this process is that clay and chalk, having different specific gravities, tend to separate in the settling tank. Another objection is the length of time required to dry the materials or get rid of the excess water.

“In the dry or semi-wet method, the raw materials are ground dry separately and mixed with only enough water to form a paste or slurry, which is then molded into bricks to facilitate the charging into the kilns. Where the rotary kiln is used, the forming into bricks is unnecessary. Sometimes the dry-press is used in forming the bricks, thus saving the expense of evaporating the excess water. In all the California cement works the rotary kiln is used, and hence the briquetting is unnecessary.

Burning. - After the materials are mixed in the proper proportions, the next step is the burning in kilns, of which there are different types on use in this country (circa 1906).

“The rotary kiln is the only one in use in California, and is now almost universally used throughout the United States (circa 1906), while rapidly growing in favor abroad. It consists of a steel cylinder lined with firebricks. The first rotary kilns were 40 feet long, but this was soon changed to 60 feet, which has been the standard length for several years. Recently Edison constructed a kiln 150 feet long, which shows a considerable saving in fuel and an increased output. This result has already induced several manufacturers to lengthen their kilns, but the 60-foot kilns are still in use in California . The cylinders are slightly inclined and revolve upon two, sometimes three tires, resting on idlers, and are turned by steam power. The upper end of the kiln projects into a brick flue, which is generally surmounted by an iron stack. The lower end of the kilns is closed by a firebrick hood. The raw material is fed into the upper end and the fuel burned at the lower end. The material works slowly down the interior of the kiln into gradually higher temperatures. First the moisture is driven off, next the carbonic acid, and next there is a partial fusion into yellow balls, which finally change to a greenish-black slag or clinker; when the burning is complete the clinker drops through the opening in the hood into the clinker pit. Each of these processes takes place at a different temperature, the last one requires the greatest care, as either overburning or underburning injures the value of the cement.

“The first work done with the rotary kilns was with oil for fuel, but in eastern Pennsylvania, coal, which is cheaper there than oil, replaced the oil and is used by first crushing it to a powder and then blowing it into the kiln. In California , however, oil, being much cheaper, is used exclusively, and aside from cheapness is preferable to coal.

“The clinker is cooled in several ways. Some use rotary coolers, some vertical coolers, and some cool in the pits or on the floor. Water is generally sprinkled on the clinker, which helps cool it and also aids in seasoning it.

Grinding. - After cooling, the clinker is ground to a fine powder either in the Griffin mill or in the ball and tube mills, such as are used for grinding the raw materials. The cement is ground until a large percentage of it (90 per cent or more) will pass through a 100-mesh screen, and a smaller but still large percentage would pass through a 200-mesh sieve. Many contracts call for a specified degree of fineness.

“The cement should be stored for several weeks, or better, several months, before using. This is usually done in large bins in the storage warehouse. When sent to market, it is shipped in either bags or barrels. Nearly all the California product is shipped in bags holding 95 pounds each.

“The Griffin mill, which is the kind used at Colton, is an American invention, and is used extensively in the cement works in the eastern United States. It consists of a revolving pendulum, with a ball at the lower end, which in its rotation strikes the lower side of a steel ring, the grinding being produced partly by the blow and partly by the peculiar rubbing motion.

“The ball and tube mills are used at Suisun and Napa Junction. The ball mill is a short cylinder, having heavy perforated steel plates inside of screens near the outside cylinder. It is charged with quite hard steel balls from 3 to 5 inches in diameter, and when the cylinder is rotated the balls drop with considerable force on the rock material below. The ball mill is quite effective crushing the material to about 20-mesh size. The tube mill is used to continue this process until extreme fineness is produced. It consists of a tube usually about 22 feet long and 52 inches in diameter, although the size is not always uniform. It is charged with well-rounded pebbles, usually imported from Norway or Sweden. The Suisun factory uses some pebbles from the American River. After the cement to be ground is placed in the mill, rotation is started and the rolling and running action of the pebbles reduces the cement to extreme fineness. The expense of keeping these mills in repair is said to be very great, not infrequently the annual cost of repairs being equal to one third the original cost of the mill.

Analysis of Portland Cement

“At present (1904) there are three cement factories in operation in California, located at Napa Junction, Napa County; at Colton, San Bernardino County; and at Cement, near Suisun, Solano County. At other places cement works are projected in the near future. The oldest factory is that at Colton . The one at Suisun began in 1902, and the one at Napa Junction in 1903.

References to Literature on Lime and Cement.

  1. Lime and Cement Industries of New York. Bulletin No. 44, New York State Museum, November, 1901.
  2. “Report on Portland Cement Industry.” Geological Survey of New Jersey, Annual Report of the State Geologist for the year 1900, pp. 9-101.
  3. American Cements, by U. Cummings. Boston, 1898.
  4. Limes, Hydraulic Cement, and Mortars, by Q. A. Gillmore, N. Y., 1872.
  5. Manual of Lime and Cement. N. Y., 1893.
  6. Eighth Annual Report of State Mineralogist of California, 1888, p. 865.
  7. “Report on Portland Cement in Indiana.” Twenty-fifth Annual Report, Department of geology and Natural Resources, 1900, pp. 1-331.
  8. Concrete - A monthly publication, began in 1904. Detroit, Michigan .
  9. Geological Survey of Ohio, 4th Series, Bulletin No. 3. The Manufacture of Hydraulic Cements, by A. V. Bleininger.”

[Top of Page]