The Influence of Concrete Cover to Protect Reinforcing Bar on Load Carrying Capacity of Floor Slab

AbstractMonolithic reinforced concrete building frame becomes prevailing structural design choice in the last ten years in Mongolia. But it is observed from the study that slabs in those buildings experience cracking problems. Commonly think that these cracks are due to shrinking effects of concrete and seriousness of them is underestimated mainly from structural point of view. Even that they are serious durability issues of the structure and further of the building. In this paper the study of cracks developed in the cast-in-place reinforced concrete slabs, their possible sources and negative impacts like structural failure is provided. Two kinds of cracks for monolithic floor slab are occurred for several buildings. One begins from the upper part of floor slab which is connected to beam along floor beam. Others form in lower part of the floor beam and in the middle. These cracks are caused by reinforcement position changed for floor slab during construction. When reinforcement position for floor slab is changed by few millimeters, load carrying capacity of the floor slab is decreased, as shown in LIRA-9.4 program structural analysis