Smiths Road and Williams Road Overpasses: Qld
The overpass structures are constructed with Super T pre-cast beams with a 40Mpa concrete topping.The concrete topping showed excessive drying shrinkage cracking ranging from 0.1mm - 1.0mm in size. The cracking was caused due to extreme weather conditions during the day of the concrete pour.
The repair method was to apply the total area with Xypex Gamma Cure, followed by a flow coat of Xypex Concentrate. The total area was then sprayed with Xypex Gamma Cure to accelerate crystalline growth and to assist as an evaporation retardant. This then was followed by 7 days of mist water curing under hessian.
Xypex Concentrate was chosen by the Department of Main Roads because of its ability to bridge and seal the cracks existing in the deck and to enhance the ongoing durability of the concrete.