Print Email Facebook Twitter Viscoelastic stress modeling in cementitious materials using constant viscoelastic hydration modulus Title Viscoelastic stress modeling in cementitious materials using constant viscoelastic hydration modulus Author Hansen, W. Liu, Z. Koenders, E.A.B. Faculty Civil Engineering and Geosciences Department Structural Engineering Date 2014-05-28 Abstract Viscoelastic stress modeling in ageing cementitious materials is of major importance in high performance concrete of low water cement ratio (e.g. w/c ~0.35) where crack resistance due to deformation restraint needs to be determined. Total stress analysis is complicated by the occurrence of internal stresses due to shrinkage, which requires estimating the stress relaxation effect from tensile creep. This study presents a new and direct methodology for viscoelastic stress analysis based on measurement of the viscoelastic hydration modulus. Autogenous shrinkage, if restrained, creates an internal tensile stress condition which is uniform within a cross section. Autogenous shrinkage stresses develop within the porous hydration products. They are compressive stresses and if restrained by reinforcement a net tensile stress develops. Results show that the viscoelastic hydration modulus is approximately 8000-9000 MPa and is a constant material property. Total stress analysis can now be separated into two components, an elastic stress based on the Young’s modulus (typically in the range of 28000-34000 MPa) and a viscoelastic (time-dependent) stress based on measurement of timedependent strains (creep and shrinkage). The importance of reducing paste content for shrinkage stress control is demonstrated using the Pickett’s model. Subject autogenous shrinkageHigh Performance Concrete (HPC)shrinkage stressesmodeling viscoelastic effects To reference this document use: http://resolver.tudelft.nl/uuid:6f2fe376-15f1-423b-b8a1-9699e41814a4 Publisher DCMat Ageing Centre, Delft University of Technology ISBN 978-94-6186-314-0 Source AMS 14: Proceedings of the 1st Ageing of Materials & Structures Conference, Delft, The Netherlands, 26-28 May 2014 Part of collection Institutional Repository Document type conference paper Rights (c) The authors Files PDF 306359.pdf 737.41 KB Close viewer /islandora/object/uuid:6f2fe376-15f1-423b-b8a1-9699e41814a4/datastream/OBJ/view