REHABILITATION OF THE COLȚEA COLLECTOR SEWER
Pilot project
Client: Apa Nova Bucharest
Innovative materials and technical solution: FS Technologies and Management
Following the emptying and inspection carried out on June 14, 2014, on the 120/180 ovoid concrete sewer, located on Colțea Street, on the section between Slănic Street and Bd. I.C. Brătianu, in a length of approximately 110 m (see situation plan), the following results were found:
- Cracks in the walls of the collecting sewer
- Severe erosions of the collector walls in the lower third
- Deteriorations in the area of connections with other pipes.
The damages were caused by:
- Pressurised water leaks
- Chemical attack on the drum caused by fermentation gases.
- Mechanical action
Rehabilitation solution:
- Cleaning the sewer with pressurized water in order to remove the chemically attacked concrete layer and any other non-stick material.
- Preparation of cracks and fissures for local injection and repair of concrete with dispersed polyvinyl alcohol fibre mortars. Injection of cracks with special mortar.
- Sealing of the collector sewer: injection with special mortar for cracks subjected to water pressure.
- Repairs to lateral connections with other pipelines (when the sealing around the pipeline is poor due to shrinkage, concrete segregation and erosion caused by the high speed flow of water). Structural fibre reinforcement and waterproofing protection.
- Reinforcement with structural fiber system based on PBO fiber and mineral adhesives (considering the stress condition that develops in such a structure with maximum moments at the key of the vault). The same system was applied in the cracked areas locally on the sides as well as at the connections.
- Application of anti-corrosion protection on the entire surface. The protection is resistant to the action of waste water and fermentation gases.
