Complete the sentences by filling in the correct word that fits a statement (gap fill). Choose the appropriate words from the word bank given below

A. elasticity B. thawing C. permeability D. hazard

E. cement F. consumption G. leaching H. precast

I. resistance J. plain K. environments L. cellular

1. The fly ash is an industrial waste and great …… for our environment.

2. Lime fly ash …… concrete is one of the important building materials which can be produced from fly ash.

3. The use of fly ash increases the modulus of …… of concrete.

4. Fly ash provides lower …… of lime liberated during hydrating of cement.

5. Adding fly ash to concrete ensures greater …… to attack of aggressive waters.

6. One of the advantages of fly ash concrete over the corresponding plain cement concrete is lower water and air …… .

7. Superior resistance to freezing and …… is another positive feature of fly ash concrete.

8. The cost of fly ash is negligible as compared to that of the …… .

9. The use of fly ash concrete brings about a substantial saving in cement …… .

10. Concrete with approved quality fly ash does not induce corrosion of reinforcing steel even in marine and industrial aggressive …… .

UNIT 16 Steel Building Designs –

Flexibility and Innovation (Part I)

Read, translate the following text and be ready to fulfil the tests:

Steel building - a structure built from pre-engineered or prefabricated pieces of steel. In general steel buildings have been well suited historically for smaller construction projects like storage sheds, grain storage facilities and airplane hangars. More recently steel has found its way into advanced farm buildings, riding arenas, commercial centers and more. Innovative general contractors often employ a mix of metal building technologies with conventional concrete block or tiltwall construction to deliver larger buildings that provide quality commercial buildings while keeping construction costs at a manageable level.

Prefabricated steel buildings provide an excellent alternative for many applications. In specialized circumstances where a large clear span is needed, a steel building or steel / concrete building will normally be the best solution. For most larger buildings, and those with greater durability requirements, however, a careful analysis will often demonstrate that a concrete tilt-up building or a blend of steel systems and concrete offer the best mix of cost-effectiveness and long term value.

Advantages. Steel is a "green" product; it is structurally sound and manufactured to strict specifications and tolerances. It is also energy efficient. Any excess material is 100% recyclable.

Steel does not warp, buckle, twist or bend, and is therefore easy to modify and offers design flexibility. Steel is also easy to install.

Steel is cost effective and rarely fluctuates in price.

Steel allows for improved quality of construction and less maintenance, while offering improved safety and resistance.

With the propagation of mold and mildew in residential buildings, using steel minimizes these infestations.

Disadvantages. Heat conductivity: Calculations show that the web of an 18-gauge steel stud is about 31 times thinner than a "two-by" wood stud; however, steel conducts heat 310 times more efficiently than wood.

Corrosion: Faulty design leads to the corrosion of iron and steel in buildings.

Types. Some common types of steel buildings are "straight-walled" and "arch," or Nissen or Quonset hut. Further, the structural type may be classed as clear span or multiple span. A clear span building does not have structural supports (e.g. columns) in the interior occupied space. Straight-walled and arch types refer to the outside shape of the building. More generally, these are both structural arch forms if they rely on a rigid frame structure. However, curved roof structures are typically associated with the arch term.

Components. There are five main types of structural components that make up a steel frame - tension members, compression members, bending members, combined force members and their connections. Tension members are usually found as web and chord members in trusses and open web steel joists. Ideally tension members carry tensile forces, or pulling forces, only and its end connections are assumed to be pinned.

Compression members are also considered as columns, struts, or posts. They are vertical members or web and chord members in trusses and joists that are in compression or being squished. Bending members are also known as beams, girders, joists, spandrels, purlins, lintels, and girts.

Each of these members have their own structural application, but typically bending members will carry bending moments and shear forces as primary loads and axial forces and torsion as secondary loads. Combined force members are commonly known as beam-columns and are subjected to bending and axial compression. Connections are what bring the entire building together. They join these members together and must ensure that they function together as one unit.

Read and memorize the active vocabulary to the text:

Active Vocabulary

1. prefabricated заводского изготовления, изготовленный заводским способом, сборный

2. storage хранение, складирование, накопление, аккумулирование

3. facility объект, сооружение, установка, средство, оборудование, пункт, предприятие

4. advanced передовой, прогрессивный, современный, перспективный, усовершенствованный, модернизированный

5. to deliver снабжать, поставлять; подавать, производить

6. manageable удобный в управлении, контролируемый, легко управляемый

7. circumstance обстоятельства, условия

8. clear span подмостовой габарит, пролёт в свету (между опорами моста), пролёт моста, свободный пролёт, свободный участок

9. solution раствор; решение

10. durability долговечность, износостойкость

11. cost-effectiveness экономическая эффективность

12. tolerance допуск, допустимая доза, предельно допустимые или достижимые параметры (устройства), устойчивость, стойкость

13. recyclable подлежащий вторичной переработке, повторному использованию; преобразуемый

14. to warp искривляться, деформироваться

15.to fluctuate колебаться, быть неустойчивым, меняться

16. propagation распространение, прохождение, продвижение

17. conductivity удельная проводимость; проницаемость

18. gauge калибр; измерительный прибор (давления или уровня)

19. bending изгиб, выгибание, изгибание

20. chord хорда, обвязочный брус, пояс (фермы, балки), соединительное русло, спрямление

21. strut стойка, опора, подкос, распорка;

крепить распорками

22. joist балка (перекрытия, подвесного потолка, пола, крыши); вспомогательная балка

CONTROL TESTS

TEST I

Decide whether these statements are true or false:

1. a). Innovative general contractors often employ a mix of metal building technologies with environmental engineering to deliver larger buildings.

b). Innovative general contractors often employ a mix of metal building technologies with conventional concrete block or tiltwall construction to deliver larger buildings.

c). Innovative general contractors often employ a mix of metal building technologies with common masonry construction to deliver larger buildings.

2. a). Prefabricated steel buildings provide construction of large steel office houses or retail centers.

b). Prefabricated steel buildings provide construction of manufacturing buildings or warehouses.

c). Prefabricated steel buildings provide an excellent alternative for many applications.

3. a). With the propagation of mold and mildew in residential buildings, using steel minimizes these infestations.

b). With the propagation of mold and mildew in residential buildings the expanding use of steel buildings would be a salvation.

c). With the propagation of mold and mildew in residential buildings, a combination of a steel roof and rigid frame is necessary.

4. a). Steel is cost-based and rarely fluctuates in price.

b). Steel is unprofitable and rarely fluctuates in price.

c). Steel is cost effective and rarely fluctuates in price.

5. a). Steel allows for improved quality of construction and less maintenance, while offering a wide range of disadvantages.

b). Steel allows for improved quality of construction and less maintenance, while offering improved safety and resistance.

c). Steel allows for improved quality of construction and less maintenance, while offering low heat conductivity.

TEST II

Match words in columns A and B (synonym match):

A B

1. to suit a). to measure b). to indicate

c). to correspond d). to lend

2. to employ a). to equip b). to utilize

c). to follow d). to mark

3. conventional a). ordinary b). clear

c). flexible d). various

4. to fluctuate a). to manufacture b). to vary

c). to produce d). to encourage

5. faulty a). resultant b). angular

c). precise d). improper

6. careful a). unobtainable b). accurate

c). adhesive d). available

7. secondary a). modern b). man-made

c). subordinate d). tolerant

8. torsion a). twisting b). force

c). clinker d). provision

9. curved a). dispersed b). raised

c). paid d). distorted

10. to subject a). to rise b). to expose

c). to expand d). to apply

TEST III

Select the best possible answer out of the choices from the list to the statements (multiple choice):

1. In general steel buildings have been well suited historically for … .

a. quality commercial buildings.

b. advanced farm buildings.

c. smaller construction projects.

d. residential buildings.

2.In specialized circumstances where a large clear span is needed, … .

a. prefabricated steel buildings can be erected more quickly than traditionally constructed buildings.

b.a steel building or steel/concrete building will normally be the best solution.

c. the project's design phase is reduced considerably with the use of the steel building system.

d.steel is used very successfully for structures as large as barns and agricultural facilities, work shops, sports facilities.

3. Steel is a "green" product; it is structurally sound and … .

a. the main reason for the expanding use of steel buildings is construction cost.

b. prefabricated steel building kits are generally less expensive than custom-designed structures built using traditional construction

c. builders can craft beautiful facilitiesthat avoid the traditional "tin shed" look associated with steel buildings.

d. manufactured to strict specifications and tolerances.

4. Combined force members are commonly known as … .

a. beam-columns and are subjected to bending and axial compression.

b. web and chord members in trusses and open web steel joists.

c.beams, girders, joists, spandrels, purlins, lintels, and girts.

d. columns, struts or posts.

5.Steel does not warp, buckle, twist or bend, … .

a. so it can be used for large buildings like commercial aircraft hangars and sports arenas, where a large clear span space is required.

b.and the prefabricated kit does not require significant customizing.

c. and is therefore easy to modify and offers design flexibility.

d. and site preparation for large steel buildings is comparable with similarly sized tilt-up structures.

TEST IV