SCALING OF THERMAL DAMAGE OF CEMENTITIOUS MATERIALS
Keywords:
fracture energy, thermal damage, high temperature, concrete model, cement paste, micro-macroAbstract
Within the framework of the study of concrete structures subjected to fire, a theoretical and experimental work has been achieved. The aim of this study is to investigate and to model the damage mechanisms of concrete after exposure to high temperature. The multiphase Digital Concrete Model and the damage model, MODEV, implemented on finite-element software SYMPHONIE, were used simultaneously to model the thermal damage of concrete exposed to high temperature. In order to validate the thermal damage model, an experimental investigation was carried out. The measurement of the mechanical characteristics of 5 cementitious materials, cement paste, mortar, ordinary concrete and 2 HPC concretes were performed by 3-point bending tests after heating/cooling cycles at 120, 250 and 400°C. The experimental tests on the 3 different cementitious materials compared to numerical simulation are presented for temperatures up to 400°C. After the validation of the models, several applications have been investigated, such as fire resistance of concretes.
Downloads
References
Bazant Zdenek P, Prat C. Effect of temperature and humidity on fracture energy of concrete.ACI Materials Journal. Technical paper Title no 85-M32. 1988.
Baker G. 1996. The effect of exposure to elevated temperature on the fracture energy of plain concrete. Mater. & struct. 29(19): 383-388
Diederichs U, Jumppanen U-M, Penttala, V. Behaviour of high-strength concrete at high temperatures. Helsinki University of Technology, Department of Structural Engineering, Report 92. 76 pages
Lemaître J., Chaboche JL., 1988. Mécanique des matériaux solides. Dunod-1988
Mounajed G, Hng Quoc H, Boussa H. Development of a new concrete damage model “MODEV” in SYMPHONIE F.E. code: Application to metallic anchor bolts. Poromechanics II, proceedings of the second BIOT conference on Poromechanics, (2002), Grenoble, France
Mounajed G. 1991. SYMPHONIE, finit element software, CSTB, France. www.cstb.fr
Mounajed G, Menou A, Boussa H, Pineaud A, Remond S, Cabrillac R. Comportement au feu des bétons. Approche multi échelles de l’endommagement thermique et identification expérimentale des paramètres. Revue Française de Génie Civil, Volume 7 – n°10/2003, pp 1299-1323
RILEM – 1986. Détermination de l’énergie de rupture des mortiers et bétons par flexion trois points de poutres encochées. RILEM draft recommendationR. Plasticity induced crack closure under plane strain conditions in terms of dislocation arrangement. In: Lutjering
