Text D. Concrete facts

Researchers at the University of Illinois have compiled some modern facts about the centuries-old material, concrete. In one study, portland-cement samples, exposed to carbon dioxide at pressures up to 250 at­mospheres, produced two surprising results. First, the mixture needed about one-fifth the water normally required. Second, some samples achieved a strength in 10 minutes that usually required seven days of curing. Rapid-curing concrete, if the process can be developed, would speed the production of precast concrete parts. It would allow the use of more waste products, such as the slag from steel and aluminum pro­duction, to be used in concrete. Fast-curing would also drastically re­duce the number of footprints and initials in freshly poured sidewalks.

I. Read the text ‘Concrete Facts’. Get its central idea.

II. Write out the words you don’t know. Look them up in the dictionary. Pay special attention to the word ‘concrete’.

III. Make a written translation of the text ‘Concrete Facts’.

CONVERSATION   THE UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND

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