A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Evaluation of Models for Predicting (Total) Creep of Prestressed Conrete Mixtures
Concrete experiences volume changes throughout its service life. When loaded, concrete experiences an instantaneous recoverable elastic deformation and a low inelastic deformation called creep. Creep of concrete is composed of two components: basic creep, or deformation under load without moisture loss and drying creep, or deformation under drying conditions only. Deformation of concrete in the absence of applied load is often called shrinkage. The deformation due to creep is attributed to the movement of water between the different phases of the concrete. When an external load is applied, it changes the attraction forces between the cement gel particles. This change in the forces causes an imbalance in the attractive and disjoining forces. However, the imbalance is gradually eliminated by the transfer of moisture into the pores in cases of compression and away from the pores in cases of tension. Designs typically use one of the two code models to estimate creep and shrinkage strain in concrete: the ACI 209 model recommended by the American Concrete Institute or the CEB 90 Eurocode 2 model recommended by the Euro-International Committee. The American Association of State and Highway Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) is based on the ACI 209 model. Three other models are the B3 model, developed by Bazant; and GZ model, developed by Gardner; and the SAK model, developed by Sakata. The objectives of this research were to develop performance limits for compressive creep of concrete mixtures used by the Virginia Department of Transportation, specifically concrete mixtures used for prestressed members (A-5 concrete) and to determine the accuracy and precision of the creep models presented in the literature.
Evaluation of Models for Predicting (Total) Creep of Prestressed Conrete Mixtures
Concrete experiences volume changes throughout its service life. When loaded, concrete experiences an instantaneous recoverable elastic deformation and a low inelastic deformation called creep. Creep of concrete is composed of two components: basic creep, or deformation under load without moisture loss and drying creep, or deformation under drying conditions only. Deformation of concrete in the absence of applied load is often called shrinkage. The deformation due to creep is attributed to the movement of water between the different phases of the concrete. When an external load is applied, it changes the attraction forces between the cement gel particles. This change in the forces causes an imbalance in the attractive and disjoining forces. However, the imbalance is gradually eliminated by the transfer of moisture into the pores in cases of compression and away from the pores in cases of tension. Designs typically use one of the two code models to estimate creep and shrinkage strain in concrete: the ACI 209 model recommended by the American Concrete Institute or the CEB 90 Eurocode 2 model recommended by the Euro-International Committee. The American Association of State and Highway Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) is based on the ACI 209 model. Three other models are the B3 model, developed by Bazant; and GZ model, developed by Gardner; and the SAK model, developed by Sakata. The objectives of this research were to develop performance limits for compressive creep of concrete mixtures used by the Virginia Department of Transportation, specifically concrete mixtures used for prestressed members (A-5 concrete) and to determine the accuracy and precision of the creep models presented in the literature.
Evaluation of Models for Predicting (Total) Creep of Prestressed Conrete Mixtures
R. Meyerson (author) / R. E. Weyers (author) / D. W. Mokarem (author) / D. S. Lane (author)
2002
66 pages
Report
No indication
English
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