What is the cause of creep in concrete?

The creep originates in the calcium silicate hydrates (C-S-H) of hardened Portland cement paste. It is caused by slips due to bond ruptures, with bond restorations at adjacent sites. The C-S-H is strongly hydrophilic, and has a colloidal microstructure disordered from a few nanometers up.

What is creep in structural engineering?

In more practical terms, creep is the increased strain or deformation of a structural element under a constant load. Depending on the construction material, structural design, and service conditions, creep can result in significant displacements in a structure.

What are three factors that affect creep?

The amount of creep that the concrete undergoes is dependent upon 1) the magnitude of the sustained loading, 2) the age and strength of the concrete when the stress is applied, and 3) the total amount of time that the concrete is stressed.

What are the effect of creep on building?

Creep causes: Deflection in structures under continuous loading. This may cause bridges to sag,or cladding systems on buildings to buckle. A tall building may get 50–100 mm shorter during its design life. Stress relief that reduces cracking.

What is creep in civil engineering?

Creep is a term used in materials science and civil and mechanical engineering. It describes the time-dependent behaviour of a solid which, when subjected to continuous stress deforms permanently below its yield point (the limit of elastic behaviour after which loads applied will cause permanent deformation.)

What causes concrete creep and shrinkage?

First, the source for both the effects are the same, which is loss of adsorbed moisture from the hydrated cement paste. In shrinkage, the loss is due to difference in the relative humidity of concrete and the environment, in creep it is due to sustained applied stress.

What are the causes of creep?

Some of the minor causes of creep in rail are below:

• Rails not properly fixed to sleepers.
• Bad drainage of ballast.
• Bad quality of sleepers used.
• Improper consolidation of formation bed.
• Gauge fixed too tight or too slack.
• Rails fixed too tight to carry the traffic.

What causes creep failure?

Creep failure is the time-dependent and permanent deformation of a material when subjected to a constant load or stress. This deformation typically occurs at elevated temperatures, although it may occur under ambient temperatures as well.

Which admixture is responsible for causing creep in concrete?

Some admixtures (mainly accelerators) are also responsible for causing creep in concrete.

What causes creep materials?

In materials science, creep (sometimes called cold flow) is the tendency of a solid material to move slowly or deform permanently under the influence of persistent mechanical stresses. It can occur as a result of long-term exposure to high levels of stress that are still below the yield strength of the material.

What is the difference between creep and shrinkage?

In shrinkage, the loss is due to difference in the relative humidity of concrete and the environment, in creep it is due to sustained applied stress. Second, the strain-time curves of both the phenomenon are very similar. The factors that effect creep also effects shrinkage.

How is creep caused because of starting operation of a locomotive?

How is creep caused because of Starting operation of locomotive? Explanation: Because of starting or acceleration of train the backward thrust created by its wheels tend to push the rail backwards. This is responsible for causing creep of rail.