What is the shrinkage and creep deformation of concrete?
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What is the shrinkage and creep deformation of concrete? What is its relationship with the compressive stress of concrete?
Concrete shrinkage generally refers to the contraction of concrete when it is exposed to cold or due to drying. Creep, on the other hand, refers to the gradual deformation that occurs in concrete under pressure; once the pressure is removed, this deformation does not return to its original level, or only partially returns to it
Concrete shrinkage refers to the reduction in volume that occurs during the early stages of concrete setting or as it hardens. It is generally divided into plastic shrinkage (also known as settlement shrinkage), chemical shrinkage (also known as autogenous shrinkage), drying shrinkage, and carbonation shrinkage. Large shrinkages can cause cracking in concrete. Concrete creep: The deformation of concrete that occurs under long-term loading.
Concrete shrinkage is caused by chemical reactions during the curing stage of concrete; it is short-term in nature, and becomes very small once the concrete has reached its strength. Creep is the deformation of concrete under long-term loads; it is a long-term effect, and its magnitude is also much smaller than that of shrinkage. Concrete shrinkage and creep deformation are primarily influenced by several factors: 1. The amount of water (the heat of hydration of cement and water; less water results in less deformation). 2. The quantity of cement used (the extent to which the heat of hydration has an effect is directly related to the amount of cement). 3. The temperature difference (the greater the difference between the temperature of the concrete at the time of pouring and its temperature after pouring, the greater the deformation). 4. Ambient temperature (at temperatures below 20 degrees Celsius, the heat of hydration of concrete is slower, resulting in less deformation). 5. The influence of concrete admixtures (accelerators speed up the deformation of concrete). 6. Cement brand (different types of cement used in various projects have different expansion rates)
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