The Bolte Bridge is one of the largest balanced cantilever cast in situ box girder bridges in Australia. The superstructure is built as two independent bridges of variable depth, pre-stressed concrete box girders, separated by a 1.15m clear gap between the structures.
ICL supplied this development a blend of 35% Cement and 65% Granulated Blast Furnace Slag (GGBS), to ensure maximum durability of the concrete which was to be permanently submerged and to lower the core temperature of the concrete during hydration.
Slag causes the core temperature to be reduced by 10-15 degrees Celsius when compared with straight GP mixes. The GGBS was also preferred to other materials such as Pozzolanic Fly Ash (PFA) due to the greater stability that it provided in the submerged marine environment.