Five (5) Main Causes of Cracks in Concrete
1. Drying Shrinkage Concrete by nature is a porous material. This means that when it is curing, the water in the concrete takes up space. As concrete hardens, it loses its moisture through evaporation resulting in empty capillary pores and a slightly smaller shape. This process is known as drying shrinkage. Since concrete is very rigid, this shrinkage causes an increase in tensile stress, which may lead to, cracking, internal warping, or external deflection. Concrete cracks when the drying shrinkage stresses exceed the tensile strength of the concrete. The spacing and size of cracks depend on the amount of shrinkage, degree of restraint, and amount and type of reinforcement. Drying shrinkage is the number one reason for cracks in concrete. 2. Lack of / improper use of control joints Control joints are most commonly installed in slab-on-grade concrete that is used in places such as driveways, pavements, house slabs, basement floors, and industrial spaces. Control joints are generally f