when was the concrete used? before concrete what was used in beams and columns construction?

Question

and how they fix the stones to each other what materials are used .and how stones are positioned to make slabs and clolumns?

Answer 1

Stone, brick and mortar were used before concrete.

Concrete was actually first used by the ancient Romans. They had a decent mix of sand, gravel, and cement (that they figured out how to make).

EDIT: mortar has been around since very ancient times. It is good at holding bricks together.
Stone masons were skilled at dressing stones with chisels and picks to get very smooth, level surfaces, so large stones can be placed on top of one another to make sound structures. Some Greek and Roman columns were made this way, by stacking smoothed, leveled, carved stones on top of one another.

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Answer 2

Concrete was used in the times of the Romans.
However, if your question pertains to beams and columns since the Industrial Age, the answer would be steel.
If you look at bridges that are over 30 years old, most of them will be steel, whereas newer bridges are made of reinforced concrete.

Answer 3

Concrete was invented by the Romans and can still be seen in buildings such as the Coliseum in Rome

Answer 4

Before concrete they use lime to stick the rocks together. Before that it was mud.