Ing. Industrial

Unit three

Modern buildings and structural materials

Thrust: the pressure or focrce exerted by each part of a structure on the ohter parts.

Post-and-lintel: a type of construction in wich a horizontal beam rests on two vertical supports.

Shear:the tendency of a material to fracture or break along the lines of stress, the force that strains or deforms a structure or its parts.Flying buttress:a support for walls or pillars that absorbs their outward and downward thrust. They were used in building the Gothic cathedrals.

Dead load:the total weight of all the materials in a structure; in other words, the weight of the structure itself.

Live load:the weight that will be added to a structure as a result of its use-people,furniture,cars,machines, and so on.

Impact:theforce at which the live load will be exerted on a structure. Cars have a greater impact than people,but airplanes have a greater impact cars.

Compression:the force that presses or pushes two or more materials together.

Tension:the force that stretches or pulls apart a material.

Neutral plane:the place in a material where there is neither tension nor compression.

masonry:building materialssuch as roxk,brick,or tile,often bound together by mortar or cement.

Pozzolana:a natural cement used by the Romans.

Bitumen:a binding agent made from natural tras.

Tensile strength:the ability of a material to retain its strngth under tension.

Fatigue:the tendency of a material to weaken as a result of continual changes in stress.

Steel:an alloy or mixture of iron with a smallamount of carbon or some other substance that increases its strength. Steel has great tensile srength.

Portland cement:a mixture of limestone and clay,wich is then heated and ground into a powder.

Aggregate:small stones or gravel or crushed rock used as a building material.

Concrete:a mixture of cement,aggregate,sand, and water. Is is the most important material for masonry construction inmodern times. It has great strength under compression.

Reinforced concrete:concrete with steel rods embedded in it to increase its tensile strength and resistence to shearing forces.

Bond:a union between two materials.

Prestressed concrete:a variety of reinforced concrete in which the steel rods are pulled tight in advance before pouring concrete to give the material the greatest strengthpossible.

Grout:a thin mortar or cement used as a binding agent.

Curtain wall:a wall supported by a steel or concrete structure of a building. A curtain wall does not have any support function itself, as does a bearing wall.

Riveting: the process of fastening together pieces of metal with rivets that do not have threads.

Welding:the process of fastening together pieces of metal bymelting a bonding metal beween similar metals.

Polymers:Long chainlike compounds of elements,principally hydrogen and carbon. They are the basis for many plastics and now being used to produce concrete with more strength and durability. Accordingly,they help cut concrete weight to some extent.

Vocabulary

1.-what is thrust?

2.-what does post-intel construction indicate?

3.-what is shear?4.-what kind of buildings used fluing buttresses? What was their purpose?

5.-what is he difference between dead load and live load?

6.-what is impact?

7.-waht is the difference between compression and tension?

8.-what is the neutral plane of a material?

9.-what is masonry made of?

10.-what are pozzolona and bitumen?

11.-What is tensile strength?

12.-what is fatigue?13.-what is steel?

14.-what is portland cement?

15.-what is aggregate?

16.-what materials are combined to from concrete?

17.-what is reinforced concrete?

18.-what does bond mean?

19.-how is the strength of prestressed concrete incrased?

20.-what is grout?

21.-what is the difference between a curtain wall and a bearing wall?

22.-what is the difference between riveting...