Armeringsbestemmelse i underarmerede konstruktioner: Reinforcement determination in underreinforced structures

This paper deals with the calculation of the amount of reinforcement, which secures an underreinforced concrete structure against sudden rupture in the case where a crack suddenly develops in the structure.The amount of reinforcement is determined by a work equation involving the external work and the work which the cracked structure is able to absorb. In that way the dynamic contribution from the accelerating motion, in consequence of the crack development, is taken into account.The work equation is transformed into analytical expressions for minimum reinforcement. A determination of minimum reinforcement from these expressions leads in many cases to a considerable increase compared with the amount of reinforcement required to carry the statical load.