CONSTRUCTION OF REINFORCED CONCRETE BASEMENT

The pictures illustrate the construction of a reinforced concrete basement beneath a large house in Newcastle. The excavation allows sufficient room to position the formwork for the reinforced concrete walls. Blinding concrete has been poured over the ground and a waterproof membrane has been placed. Reinforcement has been fixed for the floor slab and vertical starter bars can be seen. Note the use of 100mm x 100mm timber sections placed and fixed horizontally to allow concrete to stand 100mm upwards from the main slab at the position of walls and columns. This is to create a "kicker". It facilitates the subsequent positioning of the formwork for the columns and walls. Note that the reinforcement is ribbed to enhance the bond between the bars and the concrete. All high tensile steel bars are ribbed in this way. Note how the reinforcement is kept above the insulation to ensure sufficient cover when the concrete is placed. The concrete is to be placed by a pump and its discharge pipe is being connected together. Note how the bars are wired together to create stability within the reinforcement cage. This is essential to prevent the reinforcement from becoming displaced when the concrete is poured.