Size effect of concrete in compression, State-of-the–Art - Printable Version +- Civil Engineering Association (https://forum.civilea.com) +-- Forum: eBooks (https://forum.civilea.com/forum-63.html) +--- Forum: Journals, Papers and Presentations (https://forum.civilea.com/forum-74.html) +--- Thread: Size effect of concrete in compression, State-of-the–Art (/thread-19769.html) |
Size effect of concrete in compression, State-of-the–Art - ir_71 - 12-08-2010 Size effect of concrete in compression, State-of-the–Art Author: Gro Markeset | Size: 2.4 MB | Format: PDF | Publisher: SINTEF | Year: 2008 | pages: 33 | ISBN: 978-82-536-1009-2
Size effect is known as a relative change (decrease) of the structural properties (peak resistance, ductility, etc.) when the structure size increases. In quasi brittle materials such as concrete, this is a recognized phenomenon. For the concrete material most focus on size effect has been connected to the tensile states of stress. After the development of the Fictitious Crack Model (Hilleborg et al 1976), there have been large research activities within the field of fracture mechanics applied for concrete, particular for tensile states of stress. Based on this work it is now generally accepted that tensile failure is localized to a limited zone and that this failure localization is the source of the so-called size effect. In the new Eurocode 2 this size effect is implemented for punching and shear using a size factor k= 1+ 200 / d , where d is the member depth in mm. Compressive failure is, as in tensile failure, found to be localized to certain zones and gives rise to a size effect (Hillerborg (1988), Bažant (1989), Markeset (1993, 1994), Markeset and Hillerborg (1995), Bigaj and Walraven (1993), Janson and Shah (1997), Walraven (2007), van Mier (2007)). The compressive behaviour of concrete is one of the fundamental parameters of structural design as most load-bearing concrete elements, such as beams, columns and slabs, experience compressive strain gradients where the compressive strain at the critical section is in the postpeak (softening regime) of the stress-strain curve at failure. The presently used codes of practice do not limit their application field to some selected range of member dimensions although experimental studies have shown that size effect of concrete loaded in compression exists. In this report the size effect of compressive failure of concrete members exposed to uniaxial compression as well as compressive strain gradients is discussed. Code: *************************************** Code: *************************************** |