Freshwater is increasingly a scarce resource and wastewater produced by urban and agricultural areas is a significant source of pollution. Wastewater treatment plants therefore provide a valuable service and need to be looked after. Sika’s long term know-how and expertise is there to support Owners, Specifiers and Contractors in choosing the right sustainable solution. As the industry leader in concrete repair and protection, Sika can provide long lasting construction and refurbishment solutions to prolong the longevity of wastewater treatment plants. Sika’s wide range of repair and concrete protective solutions aims for long term sustainable refurbishment strategies, in terms of cost, time, materials and impacts.
Typical Exposures for Sewers
Heavy abrasion and erosion of the concrete and prefabricated elements are often found at the bottom of the sewers. In general rules, these elements shall be replaced and reassembled properly by bonding them in place with an epoxy adhesive. In the case of the concrete substrate, the erosion can be repaired with a high abrasion resistant mortar that will increase the service life of the substrate
Lateral walls and the crown often show localized defects of the concrete and some- times defects due to the corrosion of the reinforcement. After appropriate preparation, these defects can be repaired using sulfate resistant repair mortars.
The resistance of tamped concrete against a strong water current is generally not enough and often the full surface of the concrete is eroded. It is recommended in these zones to proceed with a full resurfacing.
Due to shrinkage or settlements, concrete in sewers often cracks. These cracks need
to be fi lled in order to prevent leakage of pollutant to surrounding ground water. It is often necessary to use expanding materials to fi ll these cracks.
Exposed tamped concrete surfaces show very low resistance against carbonation and the aggressive substances contained in the waste water. Therefore, these surfaces can be protected using EpoCem® technologies which are extremely resistant and watertight against urban waste water.
At the crown area, the structure can be protected against condensation water using a hydrophobic impregnation. Additionally, the aerial part of the sewer can suffer from biogenic corrosion or microbial induced corrosion (MIC). To repair and protect these areas a 100% Calcium Aluminate Mortar must be used.
General Refurbishment Considerations
Before defining the repair and protection strategy, the specific sewage treatment plant requirements on refurbishment must be considered. These requirements can have an important influence in determining the correct design, planning and construction procedures, together with the future maintenance works necessary for the sewage treatment plant.
Examples of such project related requirements include:
Durability
Duration of closure / Downtime
System compatibility
Total life cycle costing
Exposures / Site Conditions
Ecology
Systems Plus Knowhow
For many decades, Sika has been a reliable partner with waste water treatment plant contractors supplying products and systems on all continents. Sika has shown the industry we are a partner in whom they can trust.
The products and systems used in new waste water treatment plants, sewage facilities and retrofitted structures are thoroughly tested in Sika laboratories before being independently checked. Sika materials are further proven by long term site testing to withstand harsh conditions in the real environment.
The proposed solutions below are typical and may not be available in all countries. Check with your Sika sales representative to find the best locally available solution.