TY - JOUR
T1 - New insights into long-term chloride transport in unsaturated cementitious materials
T2 - Role of degree of water saturation
AU - Zhang, Yong
AU - Ye, Guang
AU - Yang, Zhengxian
N1 - Accepted Author Manuscript
PY - 2020
Y1 - 2020
N2 - Concrete is rarely saturated. Reliable durability design of marine concrete structures requires a solid understanding of the long-term chloride transport in unsaturated concretes. This paper presents a critical analysis of the time-dependent chloride diffusion coefficient in unsaturated cementitious materials exposed to marine environment. Evolutions of pore structure and chloride diffusion coefficient in saturated cementitious materials, along with the role of the degree of water saturation in long-term chloride diffusion, are analyzed. It is emphasized that the long-term sharp decrease of the chloride diffusion coefficient in marine cementitious materials is not primarily caused by densification of the microstructure due to hydration, but by the decreasing degree of water saturation with depth in the surface part of the materials. The effects of water/binder ratio and supplementary cementitious materials on chloride diffusion coefficient are different between saturated and unsaturated cementitious materials.
AB - Concrete is rarely saturated. Reliable durability design of marine concrete structures requires a solid understanding of the long-term chloride transport in unsaturated concretes. This paper presents a critical analysis of the time-dependent chloride diffusion coefficient in unsaturated cementitious materials exposed to marine environment. Evolutions of pore structure and chloride diffusion coefficient in saturated cementitious materials, along with the role of the degree of water saturation in long-term chloride diffusion, are analyzed. It is emphasized that the long-term sharp decrease of the chloride diffusion coefficient in marine cementitious materials is not primarily caused by densification of the microstructure due to hydration, but by the decreasing degree of water saturation with depth in the surface part of the materials. The effects of water/binder ratio and supplementary cementitious materials on chloride diffusion coefficient are different between saturated and unsaturated cementitious materials.
KW - Cementitious material
KW - Chloride
KW - Degree of water saturation
KW - Long-term transport
KW - Pore structure
UR - http://www.scopus.com/inward/record.url?scp=85075982327&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2019.117677
DO - 10.1016/j.conbuildmat.2019.117677
M3 - Article
AN - SCOPUS:85075982327
SN - 0950-0618
VL - 238
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 117677
ER -