Given that the road is heavily trafficked, indicate How exposure to CO2 can cause further problems in terms of Degradation and reduced levels of service life.
Answer 1 b) iii):
Potential for carbonation due to the presence of CO2 Generated from nearby road traffic.
Carbonation again leading to reduction in alkalinity And associated pH.
De-passivation gives rise to more general Corrosion of the steel reinforcement.
General corrosion of the steel reinforcement weakens To structure in terms of resistance to tensile stresses.
Corrosion products again cause expansion and sets up Tensile stresses in the cover.
Spalling results and exposes the underlying steel Reinforcement to further potential damage.
Freeze – thaw issues and further de-lamination.
Damage is probably a combination of carbonation and Chloride attack from the use of road salts on the exposed section on the road Side.