Concrete

== = = =** CONCRETE: **=


 * ===Type: Fine-grain concrete Ingredients: Cement, water, small stones.===

Advantages:

 * ===Cheap, fireproof and weatherproof, molds to any shape, strong in compression.===

Disvantages:

 * ===Cracks with temperature changes, weak in tension.===

 Is used in:

 * ===Arch bridges and domes===

= = = = == = = =** Reinforced Concrete: **=


 * ===Type: Fine-grain concrete with high-strength steel Ingredients: Steel bars hidden in concrete.===

Advantages:

 * ===Low cost, fireproof and weatherproof, molds to any shape, strong in compression and tension.===

Disvantages:

 * ===Can crack as it cools and hardens.===

 Is used in:

 * === Bridges, dams, domes, beams and columns in skyscrapers. ===