Concrete

This week the focus was on concrete, one of the most widely used construction materials. Again, I explored Cheltenham for five different examples. 

CONCRETE EXTRACT:

Concrete is a manufactured stone and is made with

water, aggregate, and cement in different proportions and

often with chemical admixtures. Concrete is usually

a mixture of 10-15% cement; 15-20% water;

about 60-75% aggregates, such as gravel, sand

and limestone filler; about 5 percent entrained air; and

less than 0.1% chemical admixtures.

It is often said concrete has a relatively short

history, as a building material; however, forms of

cement and concrete were used by ancient Egyptian

and early Chinese builders, and certainly the Romans

used concrete construction in the dome of the

Pantheon.