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DISADVANTAGES OF CEMENT
For centuries, one of the most common/ commonly materials used in construction has been concrete. Formed from hardened cement, concrete has been used for everything from driveways to home foundations. However, it has a variety of disadvantages that should be considered before use.
History. The use of concrete dates to many ancient/anciently civilizations. The Romans, in particular, used concrete for everything from simple/simply buildings to the cores of aqueducts. The Romans were also among the first to experiment with mixing different/differently additives into their concrete. They understood that mixing it with certain things would make it more water-resistant and less like/likely to crack under pressure.
Function. Concrete is still widely/wide known today for its durability and longevity. As with any building material, it does have its share of complete/completely acceptable alternatives. Wood is often designed to be load-bearing, particular/particularly in foundations, and can be treated to withstand the negative/negatively effects of moisture and termites.
Considerations. One main/mainly disadvantage of concrete is that all structures made from it will crack at some point. Concrete can also crack as a result of shrinkage, which happens when it dries out. These cracks develop within a few days of laying the structure. This will general/generally not limit the durability of a structure.
Effects. Another disadvantage of concrete is its low thermal/thermally conductivity. While concrete is normal/normally used as a layer of fireproofing between walls, it can be bad/badly damaged when exposed to intense heat. The concrete will help to contain the spread of a fire but will become unusable/unusably in the process.
Warning. Concrete also easy/easily corrodes when exposed to seawater. The effects are quick/quickly if the concrete is complete/completely submerged for extended periods of time. Concrete can be worn away by waves and by the sand and other materials carried by the ocean.
Ex. 24. In Unit 5 we often come across a few words with prefix re-. Make sure you know all these words and can understand them in context.
A) Translate the following words:
Verbs: to recycle; to reinforce; to react; to recreate; to remove; to replace; to reabsorb.
Nouns: reinforcement; reintegration; restocking; removal; recovery.
B) Find the sentence containing the derivatives with prefix re- in text 1 and translate them into Russian.
C) Make up your own situations with the words from the suggested list.
Ex. 25. Translate the sentences into Russian, paying attention to the words with prefix re-.
1. If the concrete has not hardened and damage is minimal the surface can be refloated and re-trowelled. 2. Disagreement exists among researchers as to the first real use of reinforcing in concrete. 3. Recycling minimizes solid waste disposal, improves air quality, minimizes solid wastes, and leads to sustainable cement and concrete industry. 4. Environmental protection also includes the re-integration of quarries into the countryside after they have been closed down by returning them to nature or re-cultivating them. 5. Fly Ash can replace about half of the required amount of Portland cement. 6. Concrete will either expand or contract as a reaction to temperature changes (as do all materials, to some extent). 7. In certain applications, lime mortar reabsorbs the same amount of CO2 as was released in its manufacture, and has a lower energy requirement in production than cement. 8. Selected waste and by-products with recoverable calorific value can be used as fuels in a cement kiln, replacing a portion of conventional fossil fuels, like coal. 9. Selected waste and by-products containing useful minerals such as calcium, silica, alumina, and iron can be used as raw materials in the kiln, replacing raw materials such as clay, shale, and limestone. 10. Concrete is a sustainable material because it is made from some of the most plentiful resources on earth; it can be made with recycled materials and is completely recyclable. 11. In many cases, workability can be restored by remixing concrete before it is cast.
Ex. 26. Translate the sentences into Russian, paying attention to the verbs to increase‘увеличивать(ся)’, to reduce ‘уменьшить, сократить(ся)’ and their derivatives and some other words with similar meanings.
1. All compositions produce high ultimate strength, but as slag content is increased, early strength is reduced, while sulfate resistance increases and heat evolution diminishes. 2. The use of materials such as brick and stone can increase the thermal mass of the building, giving increased comfort in the heat of summer and the cold of winter and can be ideal for passive solar applications. 3. Expansive cement concrete used to minimize cracking caused by drying shrinkage in concrete slabs, pavements, and structures is termed shrinkage-compensating concrete. 4. Plasticizers and can be used to lower the water content in the concrete while keeping a decent level of workability. 5. Accelerators speed up the hydration, or hardening, of the wet concrete, whereas retarders slow the hydration, or hardening, of the wet concrete. 6. A moist environment promotes hydration, since increased hydration lowers permeability and increases strength resulting in a higher quality material. 7. The advantage of using expansive cements is to induce stresses large enough to compensate for drying shrinkage stresses and minimize cracking. 8. High-strength concrete is made by lowering the water-cement (w/c) ratio to 0.35 or lower. 9. To compensate for the reduced workability, superplasticizers are commonly added to high-strength mixtures. 10. The cost of concrete can be decreased substantially while performance is increased. 11. Water reducers or retarders influence cement compounds and their hydration. 12. After the initial setting, immersion in warm water will speed up setting.
Ex. 27. Translate the sentences into Russian, paying attention to the verb to fail ‘потерпеть неудачу; отказать, не выдержать, выйти из строя; рухнуть; рассыпаться; не удаться; провалиться … ’ and noun failure ‘обрушение; поломка; авария; отказ, сбой, неисправность …’: (Failure teaches success – English proverb)
a) 1. As the climate warms, pile foundations lose their strength and will eventually fail. 2. Failing to plan such a huge project in detail can result in various elements of the job being built in the wrong order, slowing the project down and increasing the budget. 3. The house is like an old, disused building where the damp proof course has failed and the walls have become permanently wet. 4. The function of a foundation is to transfer the load from the structure to the ground (i.e. soil) supporting it – and it must do this safely, for if it does not then the foundation will fail in bearing and/or settlement, and seriously affect the structure which may also fail. 5. The rule is fairly satisfactory for thin walls on firm soil, but fails when applied to large walls, especially on soft soil.
b) 1. Allowing the concrete to freeze in cold climates before the curing is complete will interrupt the hydration process, leading to scaling and other damage or failure. 2. Footings must be loaded evenly as eccentric loading may cause tipping and failure. 3. The structural failures due to faulty workmanship or to an insufficient thickness of the walls are rare in comparison with those due to defective foundations. 4. Solid wood buildings have withstood severe storms and earthquakes when nearby buildings have suffered catastrophic failure. 5. You only have to look at pictures from any earthquake to see concrete framing which has failed: not enough steel main reinforcement, leading to bending failure: not enough cement in the concrete, leading to crumbling under load. 6. Most commonly foundation failure is caused by the movement of expansive and highly plastic soils beneath different sections of the foundation footings. 7. Failure can occur when the connections between the exterior and interior walls are inadequate.
Ex. 28. Translate the sentences into Russian paying attention to polysemantic functional word once:
1. Once bricks are sufficiently cured, they can be set on end to continue drying. 2. Once you've made enough trusses to make your wooden house sturdy attach them to the top of the walls (crossways). 3. While the far more common concrete foundation requires separate measures to ensure good soil drainage, the rubble trench foundation serves both foundation functions at once. 4. Always check how much the mixer holds so you know how much concrete can be produced at once. 5. It is nearly impossible to lower noise transmission once a house is built. 6. Money once earned is undoubtedly spent on various big and small things for your house. 7. Where hardwood floors can be sanded and refinished many times, engineered floors may be refinished only once or twice. 8. Covered bridges, although once popular, are usually not economically feasible. 9. Once the concrete is thoroughly mixed and workable it should be placed in forms before the mixture becomes too stiff. 10. Where floor, wall, and roof sheathing for light-frame construction were once commonly made from wood boards, sheathing is now commonly made from structural panel products, such as plywood and structural flakeboard. 11. Once purlins or rafters are installed, apply roofing boards for the roof sheathing.
Ex. 29. Translate the negative sentences. Pay attention to different means of expressing negation (suffixes, prefixes, negative particle, pronouns and adverbs, negative verbs)
1. Recycling not only helps in reducing disposal costs, but also helps to conserve natural resources, providing technical and economic benefits. 2. Non-decorative concrete block generally is painted or stuccoed if exposed. 3. Only the so-called stainless steels, which are costly in production, achieve the durability of natural stones. 4. Never try to make a mixture more workable by just adding more water because this lowers the strength and durability of concrete. 5. Mixing concrete by hand is a bad idea unless you only have a tiny amount to do. 6. Cements with special or unique properties should not be required unless absolutely necessary. 7. The argument that non-wood construction materials are ultimately better for carbon emissions than wood products is not supported by our research. 8. Too much water and not enough cement means concrete will be weaker and less durable. 9. Not only is wood the single major renewable building material, but it also requires less energy to manufacture than any other building material. 10. The stiffening of concrete, when it is no longer soft, is called setting. 11. Disagreement exists among researchers as to the first real use of reinforcing in concrete. 12. A common misconception with concrete is that it dries and gets hard; actually, the hydraulic cement reacts with the water in a chemical process called hydration. 13. Cement used in construction is characterized as hydraulic or non-hydraulic. 14. For winter conditions, none of the constructions met the performance criterion. 15. But wood has certain disadvantages: it burns and decays. 16. Nowadays the majority of bricks are used in non-bearing walls. 17. Exposure to unfavorable storage conditions, improper drying, or careless handling may cause the material to fall below its original grade. 18. Lack of sufficient moisture removal during pressing affects strength. 19. Lumber sawn from a log, regardless of species and size, is quite variable in mechanical properties. 20. Delamination and disintegration of the masonry are damage patterns typical for walls with many air voids. 21. Concrete, while quite strong in compression, fails quickly in tension by cracking.
Ex. 30. Translate the sentences into Russian paying attention to subordinate clauses in complex sentences and the conjunctions:
1. Modern mortars use cement as the main binding agent although hydrated lime is often introduced into the mix to make it more plastic. 2. Because the cement requires time to fully hydrate before it acquires strength and hardness, concrete must be cured once it has been placed and achieved initial setting. 3. Over time, kiln-fired bricks have grown more popular than sun-dried bricks, although both are still found worldwide. 4. While the far more common concrete foundation requires separate measures to ensure good soil drainage, the rubble trench foundation serves both foundation functions at once. 5. When the concrete has cured the tension in the wires is released and this produces a very strong but lightweight beam. 6. Although concrete is a dense material it is not completely impervious to water. 7. As the wall heats up it will expand and as it cools it will shrink. 8. Expansion and contraction also occurs due to changes in moisture content, and at the design stage this movement must be allowed for, otherwise cracking will occur. 9. Increasing emphasis on thermal efficiency means that only a few of these blocks are suitable nowadays unless additional insulation is provided. 10. Ashlar, which is a style not a material, is stone cut with great accuracy and laid on very thin mortar joints. 11. Because of its enormous expense ashlar was normally only used as a facing material and required a structural backing in the form of brickwork or rubble. 12. Stonework deserves a brief mention even though it is not particularly common in modern construction in its traditional form. 13. The most common stones are the ones that can be most easily quarried and cut. 14. If a building is constantly heated then condensation is unlikely to occur as the structure is warm. 15. Layout can usually be performed in a single day provided property boundaries do not need to be established. 16. A single day is often all that is needed, provided appropriate equipment is employed and there is access to the area. 17. Homes that are built on poor soil conditions may require a deep foundation, whereas most sites only require a shallow foundation.
Ex. 31. Insert who, which,orthatinto the complex sentences with attributive clauses. Translate the sentences into Russian.
1. Joseph Aspdin patented a material, _____ he called Portland cement, because the render made from it was in color similar to the prestigious Portland stone. 2. Masonry materials have a high thermal mass, _____ is their ability to absorb and store heat. 3. Hydraulic cements (e.g., Portland cement) harden because of hydration chemical reactions _____ occur independently of the mixture's water content. 4. The hydration products _____ produce strength are essentially the same as those produced by Portland cement. 5. Detailed information can be obtained from various manufacturers _____ produce information illustrating their products. 6. All portland cements are hydraulic cements _____ set and harden through a chemical reaction with water. 7. There is an exotic variety of floorings _____ you can choose from to decorate your house. 8. For making the house look beautiful, people choose a variety of flooring types but one thing that is equally significant is the fact _____ floors need to be maintained from time to time. 9. Almost any natural water _____ is drinkable and has no pronounced taste or odor may be used as mixing water for concrete. 10. The efforts of an engineer, _____ designs a project, and the constructor, _____ builds the project, are directed toward the same goal, namely, the creation of something _____ will serve the purpose for which it is built.
Read through text 3 ‘CEMENT’ and then choose the best subtitle from the phrases below to entitle each of the paragraphs.
E.g.: 1- b
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