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Vocabulary notes.

Reference – посилання Rectangular - прямокутний

Dimension - розмір

As regard – щодо, відносно

In order to – для того, щоб Bay-window – лихтар, еркер To work out – розробляти Shingles - галька

Stucco - штукатурка

Sash – віконна рама

Exercises

1. Find in the text the English equivalents to the following word combinations:

Вибір ділянки, зовнішний вигляд, точний розмір, розміщення отвірів, відповідати плану, повністю відрізнятися, бути придатним, відповідати намірам конструктора дерев’янавіконниця, будувати згідно розмірам.

2. Answer the following questions:

1. What things should be considered before the plans are drawn? 2. What decision should be made before plans for the house are started? 3. What is an elevation? 4. How can all features of construction be shown on the elevation? 5. What is the purpose of elevations? 6. What does an elevation show? 7. What does the choice of style of elevation depend upon? 8. What is the color choice of material for elevation governed by? 9. What materials can be used for roofs? 10. What sizes of doors are the most applicable?

Text 18 Concrete for Reinforced Concrete Structures

As a material for reinforced concrete structures, concrete must have certain predetermined physical and mechanical properties. Among other things, it must be sufficiently strong, have a high bond resistance, and be watertight enough to protect reinforcing bars against corrosion.

Also, according to the purpose of a reinforced concrete structure and exposure conditions, concrete must meet some special requirements. It must be frost resistant (it must stand up well to freezing and thawing cycles) for example, in exterior wall panels, outdoor structures, etc.; resist exposure to high temperatures for a long time; stand well attack by corrosive environments, and so on.

Concretes may be classified according to:

(a) inner structure, into "no-voids" concretes where the space between the aggregate grains is entirely occupied by a hardened binding agent; no-fines concretes using no or little sand; induced porosity concretes using aggregates and binding agents with arti­ficially produced open pores; and cellular concretes with artificially produced closed pores;

(b) average density (bulk unit weight), into super heavy concretes heavy concretes medium heavy concretes and lightweight concretes.

(c) form of aggregate, into nonporous-aggregate (usually, sand-and-broken stone) concretes; porous-aggregate concretes; concretes using special aggregates providing biological shielding, heat resistance, etc.;

(d) aggregate size, into coarse concretes using both coarse and fine aggregates, and fine concretes using fine aggregates;

(e) manner of hardening, into naturally hardened concrete; normal-pressure

moist-cured concrete; and high-pressure steam-cured (autoclaved) concrete.

F or brevity, concretes used in bearing reinforced concrete structures are referred to as:

-heavy concretes; these are "no-voids", heavy, nonporous coarse aggregate concretes using cement as the binding agent and hardened under any conditions; -porous-aggregate concretes; these are dense, medium-heavy or lightweight, coarse porous-aggregate concretes using cement as the binding agent and hardened under any conditions.

Nonporous aggregates for heavy concretes are broken stone crushed from various rock, such as sandstone, granite, and natural quartz sand. v' Porous aggregates are naturally occurring perlite, pumice or shell rock, or manufactured materials, such as ceramsite, slag, etc. Those using porous aggregates are divided into ceramsite concrete, slag concrete, perlite concrete, and so on.

In order to produce concrete having a predetermined strength and durability, one needs to mix in a correct proportion the necessary ingredients which include various cements, coarse and fine aggregates, admixtures improving the workability or frost resistance of the concrete, and so on.

The strength of concrete depends on the aggregate grading (the aggregate should be graded so that the volume of voids in the mixture would be minimal), aggregate strength and surface condition, cement grade and its amount, amount of water, etc. Uneven and rough aggregate grains provide a better bond in the mix. So, sand-and-broken stone concretes have a greater strength than sand-and ­gravel concretes.