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Concrete shrinkage and creep significantly affect the serviceability of bridges, especially long-span bridges. To investigate the long-term shrinkage and creep behaviors of low-shrinkage and low-creep C60 high-performance concrete (hereinafter referred to as LSLC HPC C60), 76 LSLC HPC C60 specimens are designed and subjected to shrinkage and creep tests for 270 days. The results indicate that the LSLC HPC C60 exhibits a similar trend in shrinkage and creep development as ordinary C60 concrete but with smaller creep and shrinkage values. New parameters for the two commonly used creep models are recommended based on experimental data. By comparing the measured data, it is determined that the parameter-recommended creep models are more suitable for predicting the creep performance of the LSLC HPC C60. A finite-element model of a long-span bridge is established, and the recommended models are imported into the bridge model. The multidecade deflections of the main span of the bridge are analyzed considering different creep models. The calculated results indicate that the parameter-recommended creep models can be used to predict the long-term deflections of long-span bridges with the LSLC HPC C60. [ABSTRACT FROM AUTHOR]

Summary: The objective of the present paper is to present a numerical study on the penetration performance of concrete targets with 2 different water contents. Numerical analysis has been performed by using the finite element code Abaqus/Explicit, in which a coupled elastoplastic damage model has been developed for saturated/unsaturated concrete under a wide range of confining pressures. The performance of proposed model has been firstly verified by simulating the triaxial compression tests and penetration tests realized with saturated/dry concretes. Comparisons of available experimental results and numerical simulations show that the proposed model is able to reproduce satisfactorily the mechanical behavior of saturated and dry concretes. A higher failure stress and a more important pores closing are generally obtained in dry concrete samples with respect to saturated ones. Furthermore, the main observed patterns of penetration test realized with saturated concrete targets are also satisfactorily simulated by the numerical results. Therefore, the proposed model is used to numerically predict the penetration performance of dry concrete target, and the penetration performance of dry/saturated concrete target is discussed. We observe that in dry concrete target, the penetration of projectile is strongly declined, and a smaller damage zone is created. The numerical predictions and discussions can help engineers to enhance their understandings on the influence of hydraulic conditions on structural vulnerability of concrete structures subjected to near‐field detonations or impacts. [ABSTRACT FROM AUTHOR]

To enhance the understanding of interaction between elastoplastic damage behavior of concrete and penetration behavior of projectile, this study develops an elastoplastic damage model for concrete with an emphasis on the pressure dependence of volume change. Numerical analysis is performed by using the finite element code Abaqus/Explicite, in which the proposed model is incorporated. In order to understand the effect of concrete volume change and concrete damage on the penetration behavior of projectile, a series of parametric studies are carried out. Finally, some projectile penetration tests are simulated by using the proposed model. The numerical results reproduce satisfactorily the main patterns observed in the projectile penetration tests. The interpretation and discussion of numerical results help the engineers and ballisticians complete their knowledge on the vulnerability of concrete structures. [ABSTRACT FROM AUTHOR]

The present paper focuses on the hydro-mechanical behaviour of concrete under high confining pressures. By using the poromechanics approach, an elastoplastic model is adopted to describe the mechanical behaviour of concrete under different saturation conditions and high confining pressures. A hydrostatic compression test with the measurement of interstitial pore pressure is firstly used to identify the model's parameter. After that, three quasi-oedometric tests with different water contents are simulated. The obtained numerical results exhibit that the mechanical behaviour of concrete is strongly coupled with its hydraulic responses. For instance: the saturation kinetics is accelerated by the plastic deformation related to pore collapse and volumetric compaction. The numerical predictions and discussions can help engineers to enhance their understandings on the influence of interstitial pore pressure on the vulnerability of concrete structures subjected to near-field detonations or impacts. • Fully coupled hydro-mechanical behaviour of concrete under high confining pressure is analysed. • Hydraulic responses of concrete under high confining pressure are simulated. • Two plastic mechanisms observed in triaxial stress state are influenced by the presence of pore water. [ABSTRACT FROM AUTHOR]