PHYSICO-MECHANICAL BEHAVIOUR OF CEMENT STRUCTURES UNDER FREEZING
Freezing and thawing can result in two kinds of damage,internal freezing (bulkdamage) and scaling (surface damage),which has prompted numerous engineering orscientific works to help improving the winter maintenance of civil engineering facilities. Here our contribution relies in building a physically-based quantitative assessment of thestress and strain in a frozen cement paste that takes account of the ability of ice,water,andsolid skeleton,to deform. This is done in the framework of poromechanics that couples theice/water mass density change,the so-called crystallization pressure,and the thermoelasticproperties of the different phases that form the porous material. At the scale of a cementstructure,Darcean liquid water movement and thermal gradient effects are also treated. This analysis reveals some key material parameters such as the pore size distribution andconnectivity of the cement paste that are experimentally estimated from its unfrozen wateramount and hydraulic permeability. In case of high thermal gradient (up to 1.5℃/mm),themodelling also indicates that skin damage can occur without a saline layer in contact with thefrozen surface. It eventually predicts that a less permeable sample is more susceptible to ascaling-like damage,which explains the observed experimental result.
coupling thermomeehanics porous media cryoscopic suction cryosuction
Teddy Fen-Chong Antonin Fabbri Aza Azouni Olivier Coussy
Université Paris-Est,Institut Navier,LCPC-ENPC-CNRS,Marne-la-Vallée,France Universite Paris-Est,Institut Navier,LCPC-ENPC-CNRS,Marne-la-Vallée,France;New address: Bureau de Re
国际会议
The International Conference on Durability of Concrete Structures(2008年混凝土结构耐久性国际学术会议)
杭州
英文
872-877
2008-11-01（万方平台首次上网日期，不代表论文的发表时间）