Properties of materials

Materials we can see around us and those used in civil engineering have various properties. The word ‘property’ can be used in many different ways. We are going to use it with the meaning of a quality or feature of something. All the things we can see around us are made of some kind of materials or, in most cases, of a combination of various materials.

We use particular materials to produce certain objects because of their properties. How do we find out what the properties of some materials are? The answer is very simple. We can see the materials or touch them; we can try lifting them or applying force to them. The materials will perform in a certain way. When we touch the material, we can feel if it is smooth or rough. Some vandals take a nail or other sharp object and scratch walls or elevator booths to find out if the material they are made of is soft or hard. We need a crane to lift a concrete block as it is really heavy, but things we can lift with our hands are obviously light. We use concrete blocks for building constructions because they are rigid. But car wheels should be flexible therefore, we use rubber for their production. We want to see through windows, so we use glass to make them. Glass is transparent, but brittle, so it can be easily broken. Glass is not tough at all. Plastics are tough, but they are either translucent or opaque, so we cannot so clearly through objects made from them. There are fire-resistance doors in office or residential buildings. They are make off non-combustible materials. Unfortunately, most of the materials we have in our household or offices are combustible, and in the case of fire, we can hardly save anything but our lives.

TEXT #25

1. Read and translate the text

2. Vocabulary exercises

3. Grammar exercises

4. Speaking tasks

Building a house

When an architect has to design a house, he draws pictures of what the house will look like when it is built. He draws preliminary plans show size of the house, shape of the rooms and where all the fitting must go in the house, together with a rough estimate of the cost, and submits them to the client for his approval. An architect has surveyors working with him. The surveyors measure the plot of land or site and make a plan. They work out what will be needed to build the house and how much it will all cost. At this stage several building contractors are invited to submit their tenders or costs. The architect assists his client in selecting the best one and helps him draw up a contract between the client and the contractor. Various types of work on the house are performed by independent crews known as subcontractors. The contractor marks out the shape of the house on the site. He does this with wooden pegs and tape. Everything is now ready for the workmen to start. They dig up the topsoil to lay the foundation. Most of the houses in Great Britain are made of bricks. The bricks keep the warmth in and weather out and support the roof. The man who builds the walls is called bricklayer. To make the walls stronger the bricks must overlap each other. When the walls are just above the ground, a waterproof layer is placed on the top which stops moisture in the ground from passing to the rest of the house. The carpenters now begin to work. A carpenter is a man who does the rough woodwork on the house. Then a joiner fixes the window ledges, and when the walls are plastered, he fixes the doors and other woodwork. When the walls of the house are too high for the bricklayer to reach, a scaffold is made. The scaffold is platform of planks for the workmen to stand on. It is held up by a framework or steel tubes. A lot of strong timber is used to make the roof. The tiler fixes the roof tiles on to the roof so that they overlap each other. When the roof is on, many different workmen come and finish the house. Plumbers work on all the water pipes to carry clean water into the house. They also lay pipes to carry waste water to away to sewers. They fix the guttering and drainpipes, which collect the rainwater the runs from the roof and take it into the drains. Glaziers put glass in the window frames to keep out the wind and the rain. The electricians have a special plan, which shows theme where to pull all the lights and plug sockets. They fasten wires to the bare walls. When all the wires and pipes are in place, the house is ready for the plasterers. They are the persons who make the ceilings and walls nice and smooth. The joiners can now finish all the woodwork in the house, and leave it ready for the painters and the decorators. Subsequently, the contractor completes the building and the client occupies it. During the six months after completion, the contractor must correct any defects that appear in the fabric of the building.

TEXT #26

1. Read and translate the text

2. Vocabulary exercises

3. Grammar exercises

4. Speaking tasks