Time- and load- dependent behaviour of flowable concrete: Progress report of fib task group 4.3

Stress and strain interaction is of vital importance for concrete structures as it has an influence on cracking, deflection and prestressing loss. With the increased range of compressive strengths and flow characteristics, the mixture composition of nowadays concretes often differs considerably from Vibrated Concrete (VC) with regard to paste...

Viscoelastic stress modeling in cementitious materials using constant viscoelastic hydration modulus

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...

Modeling and analyzing autogenous shrinkage of hardening cement paste

In this paper, a conceptual model for analyzing the plastic part of autogenous deformation of cement paste based on the Arrhenius rate theory will be presented. The autogenous deformation will be calculated from the elastic deformations with inclusion of creep. Different kinds of cement paste with a water cement ratio 0.3 are tested and studied,...

Ultra high performance concrete made with rice husk ash for reduced autogenous shrinkage

Ultra High Strength Concrete (UHPC) is generally made with low w/c mixtures and by adding silica fume. Low w/c mixtures, however, exhibit high autogenous shrinkage, while a high amount of silica fume increases the price of these mixtures. For designing ultra high strength mixtures with low autogenous shrinkage and lower costs the possibility of...