Concrete creep

Sulfur concretes creep more at room temperature than portland cement concretes, and deformation from this cause may increase rapidly with temperature (28). Excessive deflections of structural elements are an undesirable feature which could result from creep, but relief of residual stress is a potential benefit. 

The concrete creep was tested the testing data were fitted into the following equation ... 

Concrete creep and shrinkage at cyclic ambient conditions. Cement Concrete Composites,... 

Z.P. Bazant, Prediction of concrete creep and shrinkage past, present and future, Nucl. Eng. Des. 201 (2001) 27-38. 

Qinlar, E., Z. Bazant, and E. Osman (1977). Stochastic process for extrapolating concrete creep. Journal of the Engineering Mechanics Division f03(EM6), 1069-1088. 

In following the movements of the vessel during initial prestressing the stress in the liner approaches and, in some cases, reaches yield stress. During operation, when temperature has been applied, and in late life, when concrete creep has taken place, the stress in the liner is certainly yield stress. 

Prestressing loads allow for slip at anchorage, elastic shortening of concrete, creep of concrete, shrinkage of concrete, relaxation of steel stress, and frictional losses in the tendon ducts. Load factors are in accordance with the AQ/ASME Code. 

Brandt, A. M. (1965) Testing of concrete creep in non-reinforced beams subjected to bending (in Polish), Archives of Civil Engineering, 11(1) 87-93. 

There is no need here to solve this differential equation formally, since the same result can be achieved by superimposing the polymer concrete creep test results from the Maxwell and Kelvin models. This is possible since the eight-parameter model is simply the Kelvin and Maxwell models in series. Thus, the desired solution of Equation 4.42 is obtained ... 

Multiple approaches for the quantification of model-form uncertainties are presented, discussed, and applied to a nonlinear transient concrete creep engineering problem. This entry presents the application bounds of each approach such as requirements on the availability of experimental data and whether or not the approach can account for probabilistic model predictions - predictions including the quantification of parametric and/or predictive uncertainties. These approaches include the traditional adjustment factor approaches, probabilistic adjustment factor approach (an adaptation of the prior), and the Bayesian model averaging (BMA) approach. 

The outlined methodology is demonstrated through application to a concrete creep engineering problem. Creep is defined as the slow... 

Sakata K, Shimomura T (2004) Recent progress in research on and code evaluation of concrete creep and shrink age in Japan. J Adv Concr Technol 2 133-140... 

Values for the coefficient R have been proposed by Abbasnia et al. (2005) based on experimental investigations. The risk of debonding and cracking of the new layer of strengthened beams was investigated by Beushausen and Alexander (2006, 2007) where the tensile stress relaxation due to concrete creep was also taken into consideration. 

Concrete Shrinkage Concrete shrinkage effect can be simulated by applying volumetric strain to the elements of the jacket. The effect of concrete creep should also be included to take into account the tensile stress relaxation. In a previous study (Lampropoulos and Dritsos 2010), in order to include creep effects, application of a volumetric strain equal to half of the free concrete shrinkage strain was proposed. 

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