Supreme Chambers - Mumbai
The building has 11 stories and a total area of 25,000 m2. The G+10 commercial complex, constructed in 2009, is a bonded post-tensioned structure, and has two basements used for parking facilities. The total area of the basements is about 5,000 m2. The average depth of the ground water table is about the mid-height of the upper basement.
The Problem
Within about 5 years of being in service, the structure showed severe problems related to the durability of the structure. The authority carried out conventional patch repairs and strengthening using fiber-reinforced polymer systems, but these failed due to the halo effect within 2 to 3 years.
Understanding that the problem is related to corrosion, the authority approached Vector Corrosion Technologies for their expertise to carry out a detailed condition assessment and provide a solution. It was diagnosed that the condition of each type of structural element varied and multiple areas of concrete were detected to have chloride content more than the allowable limit.
1. The concrete of the retaining walls was in sound condition. However, the embedded bars were undergoing corrosion due to the leakage of water from the surroundings.
2. The columns and beams were observed to be corroding as well.
3. The post–tension tendons were snapped at multiple locations due to corrosion, resulting in the reduction of the load-carrying capacity of the slabs.
Our Solution
During Vector's evaulation, they identified areas where corrosion was actively ongoing and a heatmap from the corrosion potential survey was also generated to identify the potential hotspots that would require attention to avoid corrosion-related issues in the future.
For the columns, which were at the highest risk of corrosion, a targeted approach was used. This included the installation of Galvashield Fusion T2 Slim anodes to control the corrosion rate and cathodically protect the bars.
On the retaining walls and floors, where active corrosion was detected, Galvashield CC4 anodes were installed in a grid pattern to control the ongoing corrosion.
Where concrete repairs were needed, we used Galvashield XP anodes around the patches to mitigate the ring or halo effect. In the slab area where the PT tendons were damaged, the concrete thickness was increased. Galvashield XP was used at the top interface of the new concrete and existing chloride-contaminated concrete to avoid the ring anode effect.
The Result
The client was able to achieve a safe and functional parking area from a quick, maintenance-free, and reliable corrosion protection system, resulting in 20+ years of extended service life compared to the previous cases of conventional patch repair. Using the targeted system provided by Vector, it was made possible to preserve and protect the existing structural members of the building. This provided a significant extension to service life at significant cost savings compared to replacement.
Technology Used
These innovative products and technologies were used on this project.