Concrete Danger in Many Buildings.

Schools, offices, blocks, supermarkets, dance and bingo halls are among hundreds of buildings throughout the country in danger of collapse, a group of architects and structural engineers says in a report published recently in Britain. The report mentions a recent circular from the Department of the Environment which says that hundreds of buildings are at risk because the concrete they are made of could be unsafe.

BRICK

A brick is.best described as "a building unit". It may be made of burnt clay, of concrete, of mortar or of a composition of sawdust and other materials; in shape it is a rectangular solid and its weight is from 672 to 9 lb.

The shape and convenient size of a brick enables a man to grip it with an easy confidence and, because of this, brick-building has been popular far many hundreds of years. The hand of the average man is large enough to take a brick and he is able to handle mare than 500 bricks in an eight-hour working day.

It is necessary, therefore, far the "would-be" bricklayer to practise handling a brick until he can control it with complete mastery and until he is able to place it into any desired position.

By placing the hand over the surface of the upper part of a brick and by placing the thumb centrally down the face of the brick with the first joints of the fingers on the opposite face, the brick may be securely handled. It is necessary to protect the thumb and the fingers with leather pads which also prevent the skin from rough bricks.

EXERCISES

I. Answer the following questions:

I. What materials is brick made of? 2. Why brick-building has been popular for many hundreds of years?3. What is the shape of a brick? 4. What is the brick's weight?

II. Read and translate the following word combinations:

the shape and size of a brick; with an easy confidence; the width of a brick; with complete mastery; to place a brick, into adesired position

III. Translate the following sentences:

1. A brick can be made of burnt clay. 2. Brick-building has been popular for many hundreds of years. 3. A "would-be" bricklayer must practise handling a brick until he can control it with complete mastery. 4- A bricklayer is able to place a brick into any desired position. 5. The bricklayer's thumb and the fingers must be protected with leather pads.

IV. Translate the text using a dictionary:

Rolling Stand. The stand fabricates large-size rolling stand structural products for residential, civic, industrial and farm construction, employing the vibration-rolling process. The recognized features of the stand are:

— continuity of the production process;

— versatility of the stand. It is capable of turning out both plain and ribbed products from common or lightweight (ceramsite) concrete in a wide range of sizes with minimum resetting at moderate cost;

— high dimensional accuracy of large-size panels which is conducive to saving of labour and time on the site;

— homogeneous structure and invariably stable physico-mechanical properties of the product.

Dry components of the concrete mix are fed to a concrete mixer in predetermined amounts, using special feeders. In the mixer, the ingredients are mixed with water and the mix is poured in a continuous stream onto a moving moulding belt through a chute. For uniform distribution of the mix use is made of a concrete placer and the compacting operation is taken care of by a vibrator screed arranged under the belt. The surplus top layer of mix is removed by a vibrating shield arranged above the moulding belt and forming an integral part of the concrete placer, whereas the final sizing of the product for thickness and imparting it a smooth finish are the operations performed by a vibrating and floating unit arranged after the concrete placer. After sizing, the moulding belt brings the product into a steam chamber.

To prevent concrete from contacting steam in the chamber, a rubberized belting cover is applied to the top surface of the product while this is in the chamber. On leaving the steaming chamber, the product is automatically removed from the moulding belt and transferred onto a tippler by means of a roller conveyor. The tippler tilts up the finished product into the upright position and an overhead crane carries.it to a storage area. The key component of the rolling stand is the moulding belt which comprises a constantly moving endless apron_ conveyor provided with a drive and a take-up head. The carrying surface is formed by apron plates lightly fitting each other and supported by two stands of traction chains. The split-type formwork secured to apron plates is selected depending on the size and shape on the product bein fabricated.

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