Pre-stressed T-Beams are cast in special moulds.
The beams are reinforced with special High tensile wire 1770n/mm2 tensile strength , 5mm wire are stretched between stable end-anchorage points and concreted is poured over a casting bed before being allowed to sufficiently cure.
The wire are released after the concrete has achieved minimum desired strength(30n/mm2 . The length requirements for each beam is determined prior to casting to avoid wastage.
The concrete used for precast production is a specially designed mix with a 28-day compressive strength of 60N/mm², with a strict control on the quality of aggregates, sand, admixers and water used for the concrete production.
Usually, all stresses induced by loads on reinforced concrete structures are mainly carried by reinforcement bars. However, in pre-stressed members such as the beams in BBF the stresses are induced in the entire member. The end result is a structural product that is better at managing vibrations and shocks compared to conventional concrete.
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