1986

Nykyri, Pekka; Sarja, Asko

The position of reinforcement and its amount and shape have a decisive effect on the performance of a reinforced concrete beam. The use of stirrups is not always necessary, they can be omitted in some cases or replaced entirely or partly with coarse shear reinforcement well anchored at its ends. The shear strength of the beam is improved when the main reinforcement of the beam is effectively anchored to support. The behaviour of different reinforcements is compared in experiments and calculations. On the basis of the results obtained a beam reinforcement system applicable to industrial prefabrication is proposed. The system comprises the strip-like main reinforcement of the beam, in which the main bars are fastened together with thin ties or with coarse anchor bars welded at the end of the strip, as well as the shear reinforcement composed of bent or straight steel fabric, of a diagonal strip reinforcing unit or bars anchored at their ends. At the joint between the beam and column the bars have zones of their own. A report on this research has been published earlier in 1982, which dealt with principles of product development of reinforcements.