Determine the Limit State of Serviceability

Cracking Cracking of concrete should not affect the appearance or durability of the structure. The criteria of limit state of cracking for the three types of prestressed concrete members are as follows :

For type 1 Prestressed concrete members : no tensile stresses are allowed

 For type 2 Prestressed concrete members : tensile stresses are allowed but no visible cracking should be there.

For type 3 Prestressed concrete members : cracking in these members is allowed but it should not affect the appearance or durability of the structure. The acceptable limit of cracking in this case depends on the type of structure and environment. Any maximum limit to cracking is not specified in this case. But as a rough guide, it has been recommended that the surface width of cracks should not, in general, exceed 0.1 mm for members exposed to aggressive environment and it should not exceed 0.2 mm for all other members.