Задание III. Read and translate the text The ancient Romans discovered a mineral on the slopes of Mount Vesuvius.
The mineral when mixed with limestone and burned, produced cement that
hardened under water as well as in the air. This cement was harder and stronger
than the ordinary lime mortar they used.
As time passed, the new material not only became the preferred type for use in
all their building projects but changed the character of Roman construction.
Masonry of stone or brick was used to construct only the surfaces of masonry
piers and walls but the interiors were filled with large amounts of the new type of
mortar. Thus we can say that the Romans were the inventors of concret
constructions.
With the fall of the Roman Empire, knowledge of concrete construction was
lost. But in the 18th century English inventors began experimenting with both
natural and artificially produced cement.
In 1824 artificial cement, named Portland cement, was patented. This type of
cement soon became very popular and the name Portland is in common use in the
present day. Portland cement does not come from a place of that name; it was
called Portland because Joseph Aspdin, the English builder who invented the first
scientifically made cement, thought it resembled the rock on the Isle of Portland on
the Dorset Coast.
Задание IV. Answer the following questions.
1. Who discovered a mineral on the slopes of Mount Vesuvius?
2. How did the Romans produce cement?
3. What material changed the character of Roman construction?
4. What materials did the Romans use to construct the surfaces of piers and walls?
5. How did the Romans use the new type of mortar?
6. Can we say that the Romans were the inventors of concrete constructions?
7. When was artificial cement, named Portland cement, patented?