Comparison of stress-strain behaviour of self-compacting concrete and conventional vibrated concrete

The knowledge of the stress-strain behaviour of concretes is a key element in the design process of reinforced concrete elements. The toughness of a material under compression can be quantified as the area under the stress-strain curve and is essential if the material is to be analyzed for impact, earthquakes, or fatigue loading. For high-strength concrete types it is known that failure occurs in a more brittle way, resulting in a steeper descending branch and a smaller area underneath it. Almost no test results are available describing the stress-strain behaviour of self-compacting concrete. Therefore different concrete types, self-compacting concretes as well as conventional vibrated concretes are investigated in this study. Uniaxial compressive tests to measure the stress-strain curve at different concrete ages (3, 7, 14, 28 days and 3 months) are performed. For this purpose cylinders with a height to diameter ratio of 3 and different compressive strengths are used. Due to the difference in mix composition a different stress-strain behaviour is noticed for self-compacting concrete. The peak strain seems to increase as well as the toughness of the material