Durability Environmental Regionalization for Concrete Structures
Table 2
Environmental character and main reason of durability degradation of every regions.
Regions
Environmental character of primary regions
Environmental character of secondary regions
Main reason of durability degradation
I
Ia
This region has a long frigid winter which lasts 6 months or more; the January average temperature is −31~−10°C; and the number of annual snowfall days is 5~100 days with a long freezing period.
No acid rain, far from coastline
Serious freeze-thaw damage, concrete carbonation, and reinforcing steel corrosion
This region has a long dry-cold winter; the January average temperature and minimum temperature in January are −10~0°C and −20~−30°C, respectively; the number of annual snowfall days is usually less than 50 days.
Most of the parts of this region have a cold and clammy winter; the January average temperature is 0~10°C; the minimum temperature can drop below −10°C; the number of annual rainy days and snowfall days is about 150 days and 0~15 days, respectively.
Severe acid rain, concrete carbonation, reinforcing steel corrosion, and slightly freeze-thaw damage
IIIc
, closer to the coast
Chloride ion corrosion, severe acid rain, concrete carbonation, reinforcing steel corrosion
IV
IVa
This region has a long summer and no winter; the January average temperature is higher than 10°C, and average annual temperature is higher than 20°C; there is no significant difference among the four seasons, the average annual rainfall day is about 120~200 days.
, far from coastline
Concrete carbonation, slightly acid rain corrosion, and reinforcing steel corrosion
IVb
, far from coastline
Severe acid rain, concrete carbonation, and reinforcing steel corrosion
IVc
, closer to the coast
Chloride ion corrosion, concrete carbonation, slightly acid rain corrosion, and reinforcing steel corrosion
V
V
This region has a cold winter and hot dry summer; the January average temperature is −10~−22°C, and minimum temperature is lower than −40°C; the July average relative humidity is lower than 50%; the annual snowfall days is 5~100 days.
No acid rain, far from coastline
Serious freeze-thaw damage, concrete carbonation,
VI
VI
This region has a dry-cold winter and hot summer; the January average temperature is 0~−10°C; the July average relative humidity is lower than 50%; the annual snowfall days is 5~20 days.
