Reinforcement of concrete

• Steel reinforcing bars are cast into the underside of the floor with 20mm or more concrete cover below them to prevent the steel rusting and to give it some protection in case of fire
• THe thicker the concrete cover to reinforcement , the greater the resstance of the floor to fire
• Structural floors are reinforced with a combination of high tensile steel and mild steel reinforcement .
• High tensile steel is usually positioned at the bottom of the concrete floor to withstand any tensile forces
• The main purpose of mild steels rods is to assist in distributing point loads on the floor uniformly over the mass of the concrete .
• THe main reinforcement usually consists of 12mm diameter high tensile steel rods spaced from 150 to 225mm apart
• There high tensile steel will span across the floor between walls supporting the floor
• THe diameter will increase as the loads imposed and the span of the floor increases
• Mild steel rods , 6mm in diameter , are wired across the main reinforcement spaced 450 to 900mm apart and are called distrivution rods or bars
• THese distribution rods are ties to the main reinforcement with wire and keep the main reinforcing rods correctly spaced when the concrete being placed .