Particular limit state of reinforced concrete structures under emergency exposure

Abstract

The article examines the possibility of establishing specific limit state for bending of reinforced concrete structures wherein, in the explosion, technological accidents or other beyond-design impacts, the design derived from the functional state and is under destruction but did not become a freely deformable mechanism causing collapse of the structure.

Numerical experiments showed that a significant increase of strains in bent elements is caused by the plastic properties tensile reinforcement, and through inelastic deformation of the compressed concrete.

The introduction of a particular limit state in the design practice can substantially change the assessment of the behavior of buildings and constructions under emergencies caused by accidental short-term impacts and will enable to properly take into account the redistribution of effort in the bearing system when the failure of one or more bearing elements, and differentiated requirements for ‘survivability’ of various areas of the building (the evacuation routes and the rest of the room) will not prevent the evacuation of people and will reduce construction costs.