Concrete Cracks

CONCRETE CRACKS Table of Crack types in Reinforced Concrete Structures A) Structural Cracks This type of crack results from the tensions that the structure must carry due to its function. They take place in structures without projects, and when the ground problem is not solved, and are very dangerous; they have nothing to do with the concreting and the concreting conditions. In such cases you must certainly consult the relevant authorities (engineering office, university etc.). No such problem is witnessed when the structure is engineered properly and when there is no overloading. These types of cracks occur vertically to the tensile strengths in reinforced concrete agents. Cracks occurring in the middle of a simple girder interval or on a corbel bearing are of this type. B) Application Based Cracks This type of crack is seen in fresh concretes or over aged concretes. 1. Fresh Concrete Cracks Fresh concrete cracks occur within the first 30 minutes to 5 hours following the placement of the concrete to the formwork, generally in concretes with wide surfaces such as floor concretes. The depth of these cracks can reach 10 cm and their length can vary from a few centimeters to 2m. Deep and long cracks can be very harmful to the concrete in terms of its strength and durability. The two most significant reasons for fresh concrete cracks are settlement differences and plastic shrinkage. Settlement Cracks These cracks occur in newly poured concretes in which concrete cover is forgotten, cure isn’t applied and excessive water is added, in reinforced concrete agents with voids, in areas having too many reinforcements, on the reinforcements close to the surface, and when the placement isn’t done properly. In fresh concrete, the water containing cement particles rise up to the surface, while the big aggregate grains sink to the bottom. The girders and floor reinforcements close to the surface resist this replacement and the fresh concrete can not settle completely in these...