Portland cement sentence example
The quantity of Portland cement made in Ohio increased from 57,000 barrels in 1890 to 563,113 barrels in 1902 and to 1,521,764 barrels in 1908.
Hannibal is the trade centre of a rich agricultural region, and has an important lumber trade, railway shops, and manufactories of lumber, shoes, stoves, flour, cigars, lime, Portland cement and pearl buttons (made from mussel shells); the value of the city's factory products increased from $2,698,720 in 1900 to $4,442,099 in 1905, or 64.6%.
In 1890 Portland cement works were built, and there is a large trade in timber.
Limestone and clay suitable for making Portland cement are also found in Ulster county and elsewhere, and the production of this increased from 65,000 Barrels in 1890 to 2,290,955 barrels in 1908.
In the neighbourhood of Glens Falls are valuable quarries of black marble and limestone, and lime, plaster and Portland cement works.Advertisement
These can be sunk to almost any depth or brought up to any height, and are filled with Portland cement concrete.
The manufacture of Portland cement is of greater importance.
Competition produced in Lehigh county the first successful Portland cement plant in the United States in 1870.
Here it will only be said that before using Portland cement very careful tests should be made to ascertain its quality and condition.
Experience shows that, although spherical pebbles are to be avoided, Portland cement adheres tightly to smooth flint surfaces, and that rough stones often give a less compact concrete than smooth ones on account of the difficulty of bedding them into the matrix when laying the concrete.Advertisement
When mixed the concrete is carried at once to the position required, and if the matrix is quick-setting Portland cement this operation must not be delayed.
The safe tensile strength of Portland cement concrete would be something like one-tenth of its compressive strength, and might be far less.
In regard to durability good Portland cement concrete is one of the most durable materials known.
Good Portland cement is so much stronger than any lime that there are few situations where it is not cheaper as well as better to use the former, because, although cement is the more expensive matrix, a smaller proportion of it will suffice for use.
Considerable alarm was created about the year 1887 by the failure of two or three large structures of Portland cement concrete exposed to seawater, both in England and other countries.Advertisement
Indeed, no Portland cement is free from the liability to be decomposed by sea-water, and on a moderate scale this action is always going on more or less.
On the other hand, if the concrete is rough and porous the sea-water will gradually eat into the heart of the structure, especially in a case like a dam, where the water, being higher on one side than the other, constantly forces its way through the rough material, and decomposes the Portland cement it contains.
At one time Portland cement concrete was considered to be lacking in fireproof qualities, but now it is regarded as one of the best fire-resisting materials known.
The concrete itself should always be the very best quality, and Portland cement should be used on account of its superiority to all others.
Stone copings are best, but they are costly, and Portland cement is sometimes substituted.Advertisement
There is good farming land in the vicinity and Alpena has lumber and shingle mills, pulp works, Portland cement manufactories and tanneries; in 1905 the city's factory products were valued at $2,905,263.
The product termed slag cement sets slowly, but ultimately attains a strength scarcely inferior to that of Portland cement.
Some of these naturally possess a composition differing but little from that of the mixture of raw materials artificially prepared for the manufacture of Portland cement itself.
Among those who experimented in this direction was Joseph Aspdin, of Leeds, who added clay to finely ground limestone, calcined the mixture, and ground the product, which he called Portland cement.
The only connexion between Portland cement and the place Portland is that the cement when set somewhat resembles Portland stone in colour.Advertisement
True, it is possible to manufacture Portland cement from Portland stone (after adding a suitable quantity of clay), but this is merely because Portland stone is substantially carbonate of lime; any other limestone would serve equally well.
Although Portland cement is later in date than either Roman cement or hydraulic lime, yet on account of its greater industrial importance, and of the fact that, being an artificial product, it is of approximately uniform composition and properties, it may conveniently be treated of first.
The greater part of the Portland cement made in England is manufactured on the Thames and Medway.
Many different forms of kiln are used for burning Portland cement.
The material is then in a partially burnt and slightly sintered state, but it is not fully clinkered and would not make Portland cement.Advertisement
Another method of making Portland cement which has been proposed and tried with some success consists in fusing the raw materials together in an apparatus of the type of a blast furnace.
The composition of Portland cement varies within comparatively narrow limits, and for given raw materials the variations are tending = to become smaller as regularity and skill in manufacture Compost increase.
As the outcome of these inquiries it has been established that tricalcium silicate 3CaO S10 2 is the essential constituent of Portland cement.
The remaining silicates and aluminates present, and ferric oxide and magnesia, if existing in the moderate quantities which are usual in Portland cement of good quality, are of minor importance and may be regarded as little more than impurities.
The silicates and aluminates of which Portland cement is composed are believed to exist not as individual units but as solid solutions of each other, these solid solutions taking the form of minerals recognizable as individuals.Advertisement
Celite is little affected by water, and has but small influence on the setting; alite is decomposed and hydrated, this action constituting the main part of the setting of Portland cement.
In fact, excellent Portland cement can be prepared from materials free from iron.
Magnesia, if present in Portland cement in quantity not exceeding 5%, appears to be inert, but there is evidence that in larger proportion, e.g.
Another constituent of Portland cement which influences 1 V ..
The quality of Portland cement is ascertained by its analysis and by determining its specific gravity, fineness, mechanical strength Tesfing.Advertisement
English hydraulic limes are of a different class; they contain a good deal of alumina and ferric oxide, and in composition resemble somewhat irregular Portland cement.
When gauged with water and made into a mortar it sets slowly, but ultimately becomes almost as strong as Portland cement.
A case in point is the employment of hydraulic lime in place of Portland cement as grouting outside the cast-iron tubes used for lining tunnels made by the shield system.
Roman Cement is another cement of the Portland class which came into use shortly before the manufacture of artificial Portland cement was attempted.
It is made by granulating blast furnace slag of suitable composition and finely grinding the product, either alone or with an admixture of about To% of Portland cement clinker.Advertisement
The particular method of granulating slag for Passow cement produces a material which sets per se and attains a strength comparable with that of Portland cement.
The cement deposits are also of value, natural cement being valued at $118,221 and Portland cement at $2,461,494 in 1906.
Deposits of true chalk are utilized in the manufacture of Portland cement for local markets.
Marl is found in the south part of the state; limestone most largely in the north part of the lower peninsula, and the east part of the upper peninsula; and the production of Portland cement increased rapidly from 77,000 barrels in 1898 to 3,572,668 in 1907.
In all cases it is customary to fill on top of the arches with a strong Portland cement concrete to a uniform level, generally the top of the deepest beam; the floor filling is constructed and carried to this level immediately upon the completion of each tier of beams, for the purpose not only of stiffening the frame laterally, and of adding to its stability by the imposition of a static load, but also to afford constantly safe and strong working platforms at regular and convenient intervals for use throughout the entire period of the construction.Advertisement
There is a large Portland cement factory here.
In the construction of the Vyrnwy masonry dam Portland cement concrete was used in the joints.
It has been shown that the best hydraulic lime, or volcanic puzzuolana and lime, if properly ground while slaking, and otherwise treated in the best-known manner, as well as some of the so-called natural (calcareous) cements, will yield results certainly not inferior to those obtained from Portland cement.
So-called " natural cement " has been used, except during frosty weather, when Portland cement was substituted on account of its more rapid setting.
This, if the dam had been thoroughly well constructed, either with hydraulic lime or Portland cement mortar, would have been easily borne.
Marls adapted to the manufacture of Portland cement are found along the Ohio river, and in the lake region in the north.
There is a large Portland cement factory just outside the city.
The precise mechanism of the process of setting of Portland cement is not known with certainty, but it is probably analogous to that of the setting of plaster of Paris, consisting in the dissolution of the compounds produced by hydration while they are in a more soluble form, their transition to a less soluble form, the consequent supersaturation of the solution, and the deposition of the surplus of the dissolved substance in crystals which interlock and form a coherent mass.
Sodium bentonite is an additive in most clay cat litter that is made from Portland cement and used as a clumping agent.