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UNIT 8 Using Concrete Formwork in Construction




 

 

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

 

Formwork systems are widely being used in the construction industry, including bridge decks. The creation of structural elements by the formwork systems has greatly benefited the construction industry.

Basic Concrete Formwork. Due to low cost, strength, durability, and other favorable mechanical properties, concrete is widely being used as a structural construction material. To reduce transportation costs and ensure rapid construction, it is essential that the concrete is formed according to the requirements at the construction site. Concrete is required to be poured for the formation of walls, slabs, and other structural elements. The concrete pressure on formwork should be monitored carefully. The concrete formwork details must be analyzed properly so that the formwork systems are used beneficially. The commonly used form materials are wood and plywood that are disposed as construction waste. Parting agents are used for the easy separation of the form materials from hardened concrete. The parting agents are also called form releasers and de-molding materials. These materials ensure prevention of bond formation between the concrete and formwork systems. Thus, the surface of finished products is not affected when removed from the forms.

Production of Structural Elements by Concrete Formwork. Concrete formwork is used extensively in construction, with numerous types of formwork available. The building projects are more simply accomplished due to the multiple availability of formwork. When the concrete is reinforced, it is almost unyielding, ideal for big and minor construction works, and also simple and complicated structures. Concrete is poured into the formwork to produce structures, or elements of buildings.

Concrete is produced by mixing cement with materials like sand, gravel, limestone, granite, and water to create a uniform mixture. When water is added, hydration, which is a reaction of cement with water to produce a hard substance, occurs. The concrete quality influences its workability. The concrete quality is dependent upon the water type and quantity, the mold shape, hydration duration, and the cement contents. The cement quality deteriorates if excessive water is used. The cement separates from other substances of the mix, causing cracks in the cement. However, reinforced concrete is strong and resistant to cracking. Reinforced concrete has metal rods, and other elements like glass fiber.

Concrete forms use state-of-the-art robotics welding system which extends the life of welds on full concrete forms. These concrete forms receive the most concrete placement pressure. A soft alloy weld wire is utilized in the concrete form weld process. This ensures greater flexibility without sacrificing strength when the concrete form is in use. This greatly reduces, if not eliminates, broken welds. Another benefit that is extremely important to keep in mind, when choosing concrete form manufacturer, is bracing construction. It is necessary to avoid weight gain through concrete accumulation under the horizontal brace. Concrete accumulation can occur when there is an open hat section on the concrete form. Weight gain will shorten your concrete form usage and can increase the likelihood of back injuries. By enclosing the hat section, no accumulation of concrete is ensured, subsequently, no weight gain on the concrete form.

 

Read and memorize the active vocabulary to the text:

 

Active Vocabulary

 

1. formwork опалубка

2. to benefit приносить пользу, помогать

3. durability долговечность

4. to ensure обеспечивать

5. to pour заливать

6. to monitor контролировать

7. plywood фанера

8. to dispose располагать; определять

9. to harden затвердевать

10. releaser разъединяющее средство, материал или вещество

11. bond соединение

12. surface поверхность

13. to accomplish выполнять, завершать

14. unyielding недеформируемый, неподатливый

15. to deteriorate ухудшать, разрушаться

16. cracking растрескивание

17. state-of-the-art современный

18. welding сварка

19. alloy сплав

20. flexibility гибкость

21. to sacrifice жертвовать

22. injury повреждение


CONTROL TESTS

 

TEST I

 

Decide whether these statements are true or false:

 

1. a). Due to economical way of working with the concrete, it is widely being used as a structural construction material.

b). Due to withstanding compression, bending and tensile stresses, concrete is widely being used as a structural construction material.

c). Due to low cost, strength, durability, and other favorable mechanical properties, concrete is widely being used as a structural construction material.

 

2. a). To reduce transportation costs and ensure rapid construction, it is essential that the relative humidity level inside the concrete does not drop lower 90%.

b). To reduce transportation costs and ensure rapid construction, it is essential that the concrete is formed according to the requirements at the construction site.

c). To reduce transportation costs and ensure rapid construction, it is essential that the fresh concrete can be pumped through a system of pipes or hoses to the site by special concrete pumps.

 

3. a). The concrete pressure on formwork should be monitored carefully.

b). The concrete pressure on formwork should eliminate any drag that concrete can cause on the shutters to prevent its free upward movement.

c). The concrete pressure on formwork should ensurethat all parts of the slipform shuttering move simultaneously.

 

4. a). Parting agents are used for retaining the necessary shape by the concrete masses.

b). Parting agents are used for the easy separation of the form materials from hardened concrete.

c). Parting agents are used for leaving inserts for openings like doors and windows.

 

5. a). The cement quality deteriorates if pools of water are allowed to form on the surface.

b). The cement quality deteriorates if excessive water is used.

c). The cement quality deteriorates if mineral and chemical admixtures are added.

 

TEST II

 

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

 

A B

1. tobenefit a). to accomplish b). to support

c). to suspend d). to enclose

 

2. favorable a). durable b). special

c). proper d). advantageous

3. carefully a). cautiously b). mainly

c). gradually d). rather

 

4. waste a). failure b). crack

c). refuse d). effort

 

5. prevention a). property b). preclusion

c). apprentice d). investigation

 

6. to affect a). to join b). to exceed

c). to need d). to influence

 

7.state-of-the-art a). advanced b). strong

c). impressive d). solid

 

8. to sacrifice a). to award b). contribute

c). to control d). to increase

 

9. flexibility a). requirement b). resistance

c). distortion d). versatility

 

10. injury a). transfer b). damage

c). stress d). capacity

 

TEST III

 

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

 

1. The concrete formwork details must be analyzed properly ….

 

a. to ensure rapid construction.

b. to produce safe structures or elements of buildings.

c. so that the formwork systems are used beneficially.

d. to eliminate future cracking of concrete.

 

2. Reinforced concrete is strong and ….

 

a. ideal for big and minor construction works.

b. not affected when removed from the forms.

c. almost unyielding.

d. resistant to cracking.

 

3. Concrete formwork is used extensively in construction, ….

a. since it has extensive financial implications.

b. with numerous types of formwork available.

c. due to low cost and durability.

d. because it remains intact until the entire structure is completed.

 

4. Concrete forms use state-of-the-art robotics welding system ….

 

a. which ensures greater flexibility without sacrificing strength when the concrete form is in use.

b. which greatly reduces, if not eliminates, broken welds.

c. which extends the life of welds on full concrete forms.

d. which can decrease the possibilities of back injuries.

 

5. The parting agents ensure ….

 

a. prevention of bond formation between the concrete and formwork systems.

b. appearance ofa film, forming on the steel bars.

c. continuous pouring of concrete into walls of a structure.

d. proper humidity level inside the concrete.

 

TEST IV

 





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