A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Improvement of mechanical performance of reinforced high strength concrete beam by reducing autogenous shrinkage
In this work the influence of shrinkage on flexural crack width, curvature and strain in shear reinforced concrete beams is discussed experimentally. Three types of concrete with a water binder ratio of 0.3, were used to prepare the beams for flexural tests: a conventional high-shrinkage-high-strength concrete, a non or low shrinkage-high strength concrete and expansive-high strength concrete; furthermore two concretes with a water binder ratio of 0.23 were also prepared and conducted to shear tests. The mixture proportions and the mechanical properties, such as tension reinforcement ratio, yield strength of shear reinforcement, Young's modulus, compressive strength, early age deformation-induced stress before loading, etc. The effect of early age deformation on crack and curvature was investigated; strain distributions before and after loading were presented in a scheme. The shrinkage effect on the shear behaviour was also investigated. Cracking patterns as well as shear force-shear reinforcement stress relationships were shown in several diagrams. The effect of early age deformation on maximum diagonal crack width was evaluated. In conclusion, it has been shown, that the effects of shrinkage and expansion of concrete before loading on maximum crack widths as well as flexural deformation could be explained by stress change in tension reinforcement from the zero stress state in concrete at the same depth as the reinforcement. Modified truss theory underestimated the maximum shear reinforcement stress independent of the magnitude of shrinkage and the shear reinforcement ratio. However, no effect of shrinkage was observed on ultimate shear strength of beams.
Improvement of mechanical performance of reinforced high strength concrete beam by reducing autogenous shrinkage
In this work the influence of shrinkage on flexural crack width, curvature and strain in shear reinforced concrete beams is discussed experimentally. Three types of concrete with a water binder ratio of 0.3, were used to prepare the beams for flexural tests: a conventional high-shrinkage-high-strength concrete, a non or low shrinkage-high strength concrete and expansive-high strength concrete; furthermore two concretes with a water binder ratio of 0.23 were also prepared and conducted to shear tests. The mixture proportions and the mechanical properties, such as tension reinforcement ratio, yield strength of shear reinforcement, Young's modulus, compressive strength, early age deformation-induced stress before loading, etc. The effect of early age deformation on crack and curvature was investigated; strain distributions before and after loading were presented in a scheme. The shrinkage effect on the shear behaviour was also investigated. Cracking patterns as well as shear force-shear reinforcement stress relationships were shown in several diagrams. The effect of early age deformation on maximum diagonal crack width was evaluated. In conclusion, it has been shown, that the effects of shrinkage and expansion of concrete before loading on maximum crack widths as well as flexural deformation could be explained by stress change in tension reinforcement from the zero stress state in concrete at the same depth as the reinforcement. Modified truss theory underestimated the maximum shear reinforcement stress independent of the magnitude of shrinkage and the shear reinforcement ratio. However, no effect of shrinkage was observed on ultimate shear strength of beams.
Improvement of mechanical performance of reinforced high strength concrete beam by reducing autogenous shrinkage
Verbesserung der mechanischen Leistungsfähigkeit von hochfesten bewehrten Betonbalken durch Minderung der Eigenschwindung
Sato, Ryoichi (author)
2004
10 Seiten, 9 Bilder, 2 Tabellen, 3 Quellen
Conference paper
English
| British Library Conference Proceedings | 2002
Early Age Autogenous Shrinkage of Fibre Reinforced Concrete
| Online Contents | 2018
Autogenous Shrinkage of Concrete
| British Library Conference Proceedings | 1996