Text 3. Mineral binding materials

Air-hardening materials include air-hardening lime and gypseous binding materials. If mixed with water they acquire ability to harden in dry medium. Air-hardening lime is a sufficient addition for making blended cement. As for stucco (a kind of gypsum used for outdoor activities), it can set and harden quickly, this property being used for making different mortars, blended cement, architectural and building pieces of work, etc.

Hydraulic hardening materials. In a general sense this type of building materials is the main one in airport building. They have the ability to harden if mixed with water not only in air but in water too obtaining still higher solidity. This group includes the following materials: hydraulic lime, Portland cement, high-early-strength Portland cement, hydrophobic Portland cement, sulphate-resistant Portland cement, slag Portland cement and puzzolan Portland cement. We shall characterize each material mentioned.

Hydraulic lime. Being roasted to a certain degree it is used for making different solutions suitable for both dry and moist conditions.

Portland cement. Being the most important binding material it plays a considerable role in airport pavement building. Rocks containing limestones, chalk and clay serve a feedstock for making Portland cement. It is widely used as a binding element for concrete pavements, different mortars, not to mention ground strengthening. When using Portland cement one should bear in mind that it is the most valuable binding element. That's why its consumption must be limited to airport pavement building requiring high stability and strength.

Plasticized Portland cement. This type of building material possesses high water and frost resistance, this property being of great importance in building the airport pavement surface layer. Plasticized Portland cement increasing considerably the strength of concrete, it reduces cement consumption by 8–10%. Generally speaking it is expedient to use this type of Portland cement for making pavements subjected to alternate moistening and drying processes as well as freezing and thawing.

High-early-strength Portland cement. Quick growing in strength distinguishes this kind of Portland cement from the ordinary one. In 24 hours of hardening its compression strength rеаchеs 200 kg/cm² and in 3 days – 250 kg/cm². High-early-strength Portland cement is widely used for runway and taxiway building.

Hydrophobic Portland cement is similar to the ordinary Portland cement but it possesses high water-tightness and frost-resistance.

Slag Portland cement is a hydraulic binding substance hardening both in water and air. Being more resistant to corrosive waters it is widely used for making concrete slabs for runways and taxiways.

Puzzolan Portland cement also belongs to hydraulic binding substance. It has high resistance to running and poorly mineralized waters though its water-tightness and frost-resistance are lower than those of Portland cement. This type of cement can be recommended for drainage systems of a flying field.

Вправа 43. Вивчіть нові терміни:

addition ― добавка; доповнення

air-hardening lime ― вапно, що тужавіє / твердіє на повітрі

alternate ― перемінний, мінливий

bear in mind ― мати на увазі

blended cement ― змішаний цемент

concrete pavement ― бетонне покриття

consumption ― витрата

gyps(um) ― гіпс

gypseous ― гіпсовий

ground strengthening ― укріплення грунту

high-early-strength сement ― цемент, що швидко тужавіє / твердіє

hydraulic lime ― вапно, що тужавіє / твердіє у воді

hydrophobic cement ― гідрофобний цемент

medium ― середовище

mix ― змішувати

mortar ― будівельний розчин

plasticized cement ― пластифікований цемент

puzzolan cement ― пуццолановий цемент

roast ― випалювати, обпалювати

running waters ― протічна вода

set ― тужавіти, твердіти

slag Рortland cement ― шлакопортландцемент

solidity ― твердість

stucco ― будівельний гіпc

sulphate resistant cement ― сульфатостійкий цемент

thawing ― відтанення

water-tight ― водонепроникний

expedient ― доцільний, вигідний.

Вправа 47. Перекладіть назви будівельних матеріалів.

Air-hardening materials, blended cement, air-hardening lime, gypseous binding materials, stucco, hydraulic hardening materials, hydraulic lime, Рortland cement, plasticized Рortland cement, high-early-strength Рortland cement, hydrophobic Рortland cement, sulphate resistant Рortland cement, slag Рortland cement, puzzolan Рortland cement.

Вправа 49. Закінчіть речення.

1. If mixed with water air-hardening materials acquire ability to ... .

2. Air-hardening lime is a sufficient addition for ... .

3. Rocks containing ... serve a feedstock for making Portland cement.

4. Portland cement consumption must be limited to ... .

5. High-early-strength Portland cement is widely used for ... .

6. Hydrophobic Рortland cement possesses high ....

Вправа 50. Дайте відповіді на запитання.

1. What are air-hardening materials subdivided into?

2. What is stucco? Where is it used?

3. What is the difference between air-hardening and hydraulic-hardening materials?

4. What materials belong to the hydraulic-hardening group?

5. Where is hydraulic lime used?

6. What serves as a feedstock for making Portland cement?

7. What kind of Portland cement possesses higher water tightness and frost resistance?

8. What kind of cement can be recommended for drainage systems of a flying field and why?

9. What binding material is used for making concrete slabs of runways and taxiways?

Вправа 52. Перекладіть словосполучення.

Running waters; hardening substance; rocks containing lime; possessing high water tightness; valuable binding material; requiring high stability; hardening both in water and air; resisting to corrosion.

Вправа 53. Вставте прийменники in, of, for, to, from, with.

1. It is expedient to use this type … Portland cement … making pavements subjected … alternate moistening and drying processes.

2. Quick growing … strength distinguishes this kind … Portland cement ... the ordinary one.

3. They have the quality to harden if mixed … water not only … air but … water too.

4. Puzzolan Portland cement belongs … hydraulic binding substances.

5. Its water tightness is lower than that … Portland cement.

6. Slag Portland cement is resistant … corrosive waters.

Вправа 55. Підберіть означення до наявних іменників.

1. element	high
2. cement	different
3. mortars	corrosive
4. addition	valuable
5. frost resistance	ordinary
6. water	flying
7. water tightness	sufficient
8. field	low
9. quality	running

Вправа 56. Вкажіть, у якому абзаці тексту говориться про:

виготовлення змішаного цементу; найміцніший в’яжучий матеріал; будівельний гіпс; цемент; що швидко тужавіє / твердіє; матеріал, що має високу стійкість до проточних і слабомінералізованих вод; матеріал, для виготовлення бетонних плит; методи збільшення міцності бетону.

Вправа 57. Підготуйте повідомлення з тем:

1. «General Characteristics of Airport Building Materials».

2. «Man-made Stone Materials».

3. «Mineral Binding Materials»