Rail Bridge Culvert Repairs.
Mackay, Queensland

In July 2008, a joint assessment was done between Xypex and NCS on the condition of Queensland Rail's Back Creek Culverts near Mackay.

During the inspection, it was observed that there was typical concrete deterioration, mainly localised at the joints/lifting lugs and several areas that displayed insufficient concrete cover over the reinforcement. There were also several cracks evident.

Following the inspection and assessment, a report was drafted along with a specification and forwarded to Queensland Rail for their consideration. NCS were then contracted by Queensland rail to carry out the repairs and future protection of the culverts.

All deteriorated concrete was scabbled to expose a clean, sound substrate and the steel was cleaned and prepared. Xypex Megamix II was then applied in layers, to re-instate the removed concrete. Xypex Megamix II was chosen for its superior bond strength, low shrinkage, chemical durability and high strength. Xypex Megmix II also includes the active component contained in Xypex's Crystalline Waterproofing Technology.

Joints and cracks were routed out and treated with Xypex Concentrate and Xypex Patch'n Plug. The culverts were then prepared and treated with Xypex Concentrate applied to the roof soffit areas. This application is a unique chemical treatment for the waterproofing and protection of the concrete culverts. The advantage of this system is that the system will resist extreme hydrostatic pressure from either the positive or the negative sides and it becomes an integral part of the structure providing long term durability.