What are the effects of creep in concrete?
What are the effects of creep in concrete?
Depending on the construction material, structural design, and service conditions, creep can result in significant displacements in a structure. Severe creep strains can result in serviceability problems, stress redistribution, prestress loss, and even failure of structural elements.
What is the effect of creep in reinforced concrete columns?
A concrete element when kept under sustained load presents progressive strain over time, associated to the creep. In reinforced concrete columns, such deformations cause the stress increase in the steel bars of the reinforcement and may induce the material to undergo the yielding phenomenon.
What are the factors affecting creep?
Other factors affecting creep include type of cement, amount of cement paste, size and shape of concrete, amount of reinforcement (rebar), volume-to-surface ratio, temperature, and humidity.
Why is creep important in prestressed masonry?
Prestressed Concrete Masonry Creep is of particular importance in prestressed concrete masonry where it contributes to prestress losses. Prestressed concrete masonry typically involves the application of compressive stresses by a prestressing tendon to a masonry wall prior to application of the building loads.
How is the creep of concrete related to stress?
The stress-strain of concrete is not a straight line but a curve and the strain will go on increasing after a certain value without an appreciable increase in stress. The creep of concrete can be defined as the time-dependent portion of the stress that occurs as a result of stress.
How does creep affect deflection of concrete columns?
In reinforced concrete beams, creep will increase deflection over time and it may be an essential consideration in the design. In the eccentrically filled columns, creep increases the deflection and may buckle.
What is the difference between shrinkage and creep in concrete?
For small specimen thickness, the creep during drying greatly exceeds the sum of the drying shrinkage at no load and the creep of a loaded sealed specimen (Fig. 1 bottom). The difference, called the drying creep or Pickett effect (or stress-induced shrinkage), represents a hygro-mechanical coupling between strain and pore humidity changes.