EFFECT OF FREEZING-THAWING CYCLES ON THE PHYSICAL AND MECHANICAL CHARACTERISTICS OF CONCRETE
Concrete is the most used construction material in practically all of civil engineering fields due to its economical and technical advantages. However, its microstructure is porous and may be complctcly or partially water saturated. In severely cold climates, this water freezes and degradations develop gradually with the freezing-thawing cycles number, in forms of internal cracking, chipping and scaling.Frost behaviour is based on the coupling between the 9％ volumetric increase during water transformation into ice, the cryo-suction phenomena, the non frozen water transport within the porous network and the thermo-mechanical behaviour of each component of the frozen media. It is thus obvious that the frost resistance depends on the microstructure (pore size distribution and permeability) and the mechanical characteristics of the material.In this paper, physical and mechanical characteristics evolution during freezing-thawing cycles was followed. The results show that the reduction in the mechanical resistance and the elastic modulus is accompanied with an increase in the intrinsic permeability. The damage can be characterized by a scalar parameter, Df, due to frost action.With this parameter, the resistance reduction as well as the permeability evolution may be described, with a good agreement, as a function of cracks development.
concrete frost action damage permeability
Mohamed A.S.MOHAMED Elhem Ghorbel George WARDEH
1- L2MGC, Cergy-Pontoise University, 5 mail Gay LUSSAC 95031 CERGY-PONTOISE Cedex,Cergy-Pontoise, France
国际会议
长沙
英文
460-472
2009-06-05（万方平台首次上网日期，不代表论文的发表时间）