Reasons of cracks in floor slab panel

Abstract

The article considers the problem of the formation of temperature and cracks in a reinforced concrete floor in thin 400 mm, connected by reinforcing outlets with internal reinforced concrete walls and the outer ring wall of the core of a high-rise building. During the hardening of the laid concrete, the formation of through cracks in the overlapping, extending from the walls and located across the corridor formed by the walls, was observed. The paper analyzes the possible causes of cracking. Cracking occurs due to the restriction of free temperature and shrinkage deformation of the floor slab by a rigid connection with the walls. The direction of the cracks indicates that tensile shrink stresses act along the walls. Cracks form during the cooling of the concrete floor, when the directions of the vectors of shrinkage and thermal deformation coincide. The work gives recommendations for the care of concrete floor structures.