SHRINKAGE STRESS DEVELOPMENT IN CEMENTITIOUS MATERIALS
The tensile modulus associated with viscoelastic (i.e.time-dependent) deformation is of major importance in stress analysis of concrete.This paper presents experimental evidence for the differentiation between Youngs modulus due to external loading and the viscoelastic modulus associated with internal loading from shrinkage stresses generated by self-desiccation.Autogenous shrinkage deformation is the result of internal compressive stresses in the pores of cementitious reaction products.If this deformation is restrained a stress reversal develops.A comparison of free shrinkage and restrained shrinkage from steel reinforcement makes it possible to determine not only the tensile stress development from shrinkage restraint, but also the tensile modulus associated with shrinkage restraint.Stress analysis is simplified in this case since autogenous shrinkage creates a uniform stress distribution within a cross section as opposed to the analysis of drying shrinkage stresses.The shrinkage modulus was found to be a constant over time, averaging about 7,500 Mpa.Thus, it is a unique material property on par with the Youngs modulus, which reflects the instant resistance to deformation of the concrete due to external loading (e.g.thermal and mechanical).Both internal and external moduli are needed for total stress analysis.
Will Hansen Eduard A.B.Koenders Zhichao Liu Bo Meng Ya Wei
Department of Civil and Environmental Engineering,University of Michigan,USA Delft University of Technology,The Netherlands Department of Civil Engineering,Tsinghua University,China
国际会议
The Fourth RILEM International Symposium on Concrete Modelling (CONMOD 2014)(第四届RILEM混凝土材料建模国际会议)
北京
英文
204-211
2014-10-12（万方平台首次上网日期，不代表论文的发表时间）