Circular strengthening due to lack of reinforcement – Tel Aviv, Israel

Project

The tank for fresh water located in the Tel Aviv region was built in the 1940s and has a diameter of 8.40 m, a height of 6.00 m, and a concrete wall thickness of 20 cm. Despite being situated in a nature reserve, the decision was made to repair the tank, rather than replacing it, due to its historical significance.

Over the years, the concrete structure has developed cracks. After a detailed investigations and static examination of the supporting structure, a complete renovation with renewal of the waterproofing from the inside and an external reinforcement was ordered.

Solution

The rehabilitation process began by draining the water from the tank and sealing the existing cracks. To reinforce the structure, eight CarboStress? systems were installed, each with a tension force of 180 kN distributed over the height of the tank.

To minimize friction losses during the tensioning process, a unique anchorage was developed that allowed the systems to be tensioned synchronously from both sides of the anchorage. In addition, the anchors were installed staggered over the height of the tank.

Due to the low dead weight of the tendons, the installation process required only a simple scaffold and no cranes or lifting equipment was needed. To protect the anchorage areas from external impacts and heat, a steel cover was installed to protect them. Additionally, both the fresh water tank and the CarboStress? tendons were painted white.