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Are You in Boston Massachusetts? Do You Need Concrete Cutting?
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We Service Boston MA and all surrounding Cities & Towns
Boston is the capital city of the Commonwealth of Massachusetts and had granted the name from the English town, Boston, Lincolnshire. It ranked as the 24th largest city in the US. Greater Boston, is the home of 4.7 million people, making it the 10th largest metropolitan statistical area. As a commuting area in the USA, 8.1 million people live and work within its boundaries. Being a global city, it is among the top 30 most economically powerful cities in the world.
Boston was founded by Puritan settlers in 1630, who were from England. It was incorporated as a town in 1630 and was upgraded to a city in 1822, making it one of the oldest cities in the USA.
Since the foundation, Boston was a place for several historical events, such as the Boston Tea Party or the Siege of Boston. Since it gained independence from Great Britain, it has become an important port and manufacturing area, and the center of education and culture. Boston has expanded through time beyond the original peninsula of Shawmut. The historical and cultural importance of Boston attract over 20 million tourists yearly. This city has the first subway system, public school, and public park within the United States of America.
The estimated population of Boston by 2016 is 667,137, and it is the third most densely populated city in the US with a density of 13,841 people per square mile. There are hundreds of thousands of people commuting to the city daily – during special events, there might be approximately 2 million people within the boundaries of Boston. The spread out of the population – from among the residents only – is 21.9% at the age of 19 and under, 14.3 between 20 and 24, 33.2% between 25 and 44, 20.4% between 45 and 64, and 10.1% over 65. This leads to a median age of 30.8 years. The median income per capita is $33,158, and per household, this number is $51,739. Unfortunately a large percentage, 21.4% of the whole population is under the poverty line.
People if Irish origin gives the largest single ethnic group in Boston, making up 15.8% of the population. The second largest group is the Italians with 8.3% of the population. People of West India and the Caribbean are another large group, giving 6%. There are over 27,000 Chinese people in the city too, who mostly reside in the Chinatown. There are also Vietnamese, South Asians, and Hispanic people settled down in the area of Boston. This diverse ethnic composition results in an interesting and rich cultural life.
Besides the many lower educational school Boston also has highly ranked universities. The worldwide renowned Harvard University is located on the outside of Boston, which is the oldest institute of higher education in the USA. There are other major universities and colleges that belong to Boston, such as the Boston University, Boston College, the MIT, Tufts University, Bentley University, Brandeis University, and the University of MA, Boston.
Are You in Boxborough Massachusetts? Do You Need Concrete Cutting?
We Are Your Local Concrete Cutter
We have performed thousands of concrete contractor services in Boston, throughout Massachusetts, and even all of new england. We perform all of our projects with these goals in mind.
- To keep abreast of advances in new technologies and processes.
- To anticipate and meet customer needs utilizing a thorough planning process.
- To continually strive for greater efficiencies in all phases of the organization.
- To earn a fair return while being able to exceed the customer’s expectations.
- To develop creative practical solution for difficult projects.
Fine aggregate shall consist of sand, or other approved inert materials with similar characteristics, or a combination thereof, having clean, hard, strong, durable uncoated grains and free from injurious amounts of dust, lumps, soft or flaky particles, shale, alkali, organic matter, loam or other "Standard Specifications and Tests for Portland Cement," (Serial Designation C9-21) issued by the American Society for Testing Materials and adopted as standard by the United States Government, the American Engineering Standards Committee, etc. deleterious substances." Generally fine aggregate is considered to consist of particles smaller than one- quarter of an inch in diameter. The size and grading of an aggregate are studied by means of standard sieves,' made of wire cloth, the smaller sizes of which (No. 4 and finer) are designated: by the number of openings per linear inch and the larger sizes by dimension of openings. The Joint Committee recommends that not less than 85 per cent of the fine aggregate shall pass the No. 4 sieve (size of opening, 0.187 in.), and not more than 30 per cent nor less than 10 per cent the No. 50 sieve. From this specification it is plain that sand made up of grains all of one size is not satisfactory. This is because a graded sand will compact more than a uniform one, the smaller grains fitting in between the larger, thereby giving a denser and stronger mortar. The fine aggregate may be tested for the presence of fine silt, loam, clay and other water-soluble material by the decantation test and for organic impurities by the colorimetric test. In the decantation test the fine aggregate is placed in a pan and sufficient water is added to cover the sample. The pan and its contents are agitated vigorously for 15 seconds, and then after waiting 15 seconds to allow the heavier suspended particles to settle, the water is poured off. This operation is repeated until the wash water is clear. The Joint Committee limits the loss in weight by this test to 3 per cent in general. The colorimetric test consists in placing a sample of the material in a bottle partly filled with a sodium hydroxide solution which turns brown if organic matter is present, the depth of shade measuring the amount of the impurity. The limit set as a "standard color" is that produced by tannic acid when present in the proportion of one part in 4000. The most useful tests are those of the strength of mortar (defined as a mixture of cement, fine aggregate and water) or of concrete made with the given fine aggregate. The Joint Committee specifies that "fine aggregate shall be of such quality that mortar briquettes, cylinders or prisms, consisting of one part by weight of Portland cement and three parts by weight of fine aggregate. will show a tensile or compressive strength at ages of 7 and 28 days" preferably "not less than 100 per cent" of that of 1 3 standard Ottawa sand mortar of the same plasticity made with the same cement. It is still common in some localities to specify that the sand grains shall be sharp and to test the cleanliness of the sand by rubbing a little of it in the palm. Sharpness of grain, however, is not a necessary characteristic at all, nor is the feeling and appearance of sand sufficient guides to its quality. Unless it is known that any given sand has been used successfully in concrete work, it should be carefully tested as here described. Coarse aggregates shall consist of crushed stone, gravel or other approved inert materials with similar characteristics, or combinations thereof, having clean, hard, strong, durable, uncoated particles, free from injurious amounts of soft, friable, thin elongated or laminated pieces, alkali, organic or other deleterious matter. Coarse aggregate shall range in size from fine to coarse in general within the limits indicated by the table on the following page. The maximum size of coarse aggregate is rarely over 3 inches, 1 in. or 1 in. being the usual limit set for reinforced concrete work. In massive construction larger stones are often placed in the mass neither by hand or derrick, care being taken that these larger pieces, or "plums," are not too close together nor too near the face of the concrete. The Joint Committee uses the term rubble concrete for that in which is embedded stones larger than three inches and less than 100 pounds in weight, and cyclopean concrete for that with stones weighing more than 100 pounds. For testing methods, see the American Society for Testing Materials Specification C9-21 referred to in footnote and also "Tentative Methods of Making Compression Tests of Concrete" (Serial Designation C39-21T) of the A.S.T.M., reprinted as Appendix XII of the 1924 Joint Committee Report. The standard Ottawa sand is natural sand from Ottawa, Illinois, screened to pass a No. 20 sieve and retained on a No. 30 sieve. It is used as a standard on account of its uniformity. 11. Water. "Water for concrete shall be clean and free from injurious amounts of oil, acid, alkali, organic matter or other deleterious substance.
The reinforcement for concrete usually consists of steel rods, round and square, sometimes made up in the form of wire fabric for use in slabs. For columns and arches the reinforcement often consists of built-up members of structural steel shapes. The following standard sizes of bars are in use and none others should ever be called for: In European practice plain bars are commonly used. In the United States preference is given to deformed bars that are rolled with small projections to engage the concrete and prevent slipping between the two materials. Many styles of such rods are made. Square twisted bars are also used. The Joint Committee specifications provide for three grades of bars rolled from billet steel, structural, intermediate and hard, and also for bars rolled from steel rails, giving preference to intermediate grade billet steel.'
1 The Joint Committee specifies that steel shall conform to the requirements of the American Society for Testing Materials as follows: "Standard Specifications for Billet-Steel Concrete Reinforcement Bars" (Serial Designation A15-14), "Standard Specifications for Rail-Steel Concrete Reinforcement Bars" (A16-14), "Standard Specifications for Structural Steel for Bridges" (A7-24), "Standard Specifications for Structural Steel for Buildings" (A9-24), "Tentative Specifications for Cold-drawn Steel Wire for Concrete Reinforcement" (A82- 21T). Cast iron used in composite columns shall conform to "Standard Specifications for Cast Iron Pipe and Special Castings" (A44-04). These several specifications are reprinted as appendices to the Joint Committee report 1924. All reinforced concrete design proceeds on the assumption that the concrete is of definite strength and uniform quality. Until recently the realization of this assumption has been a difficult and costly matter of laboratory study and unremitting expert supervision, something warranted only on important projects. Most of the concrete made has been, and still is, very variable in quality, and this variability has made it necessary to assume low strength on which to base design stresses. Demonstration of the practicability of attaining uniformity caused the 1924 Joint Committee to specify modern methods of control of concrete making and also higher working stresses. This results in a lowering of the previously uneconomical high factor of safety which had been indicated as advisable because of more or less careless and ineffective construction methods. Obviously it is of the utmost importance that the concrete measure up to the standards set by the design specifications.