§ Mr. Rooker
asked the Secretary of State for the Environment to what he attributes the process of carbonation in his Department's main office building and the spalling of concrete with rust staining; whether calcium chloride was used as an additive to the concrete and if tests have been carried out on the level of chlorides in the concrete; and if he will make a statement.
§ Sir George Young
[pursuant to his reply, 18 March 1985, c. 342]: Carbonation of the concrete at Marsham Street is attributed to a chemical reaction with acidic solutions of atmospheric gases, notably carbon dioxide resulting in corrosion of the steel reinforcement. Calcium chloride was not used as an additive to the concrete and tests carried out have revealed that the chloride content of the concrete is satisfactorily low.