Swedish scientists have studied models to help road and bridge maintenance engineers work out how much damage salting the
roads in winter might cause to steel-reinforced concrete structures.
As the winter draws in road safety becomes paramount especially in northern climes where icy roads are a perennial problem
for motorists. Gritting and salting the roads can help reduce road traffic accidents but the use of salt, which contains
chloride, comes at a price. Corrosive chloride ions can penetrate into porous concrete and reach the metal reinforcements
within, leading to corrosion after months or years of use.
Luping Tang of the Department of Civil and Environmental Engineering, at Chalmers University of Technology, in Gothenburg,
Sweden and his colleague Dr Anders Lindvall of the Central Laboratory, at Thomas Concrete Group AB also in Gothenburg, have
looked at the effects of exposure to road salt de-icing over a 10 year and a 25-30 year service period in computer
simulations of chloride ingress into concrete structures. The models simulate heavy traffic moving at speed over such
structures.
Writing in the International Journal of Structural Engineering, the team explains that, "Chloride induced corrosion of
reinforcement in concrete is still one of the main concerns regarding durability and service life of reinforced concrete
structures. Prediction of chloride ingress in concrete is one of the important parts in durability design of reinforced
concrete structures exposed to the chloride environments."
Of the two models tested, DuraCrete and ClinConc, the latter is valid against the field data from real concrete road bridges
tested after25-30 years of exposure to salting the team says, while the former is adequate for predicting the corrosive
effects of chloride after a ten-year period. The study will not only inform those assessing existing reinforced road and
bridge structures but should allow design engineers to take into account the needs of such structures during the winter
months and ensure that they find ways to reduce or even avoid potentially damaging chloride ingress.
摘自http://www.sciencedaily.com/releases/2012/11/121105081505.htm)>http://www.sciencedaily.com/releases/2012/11/121105081505.htm