As the water industry continues to navigate the challenges of managing environmental impact, meeting budget targets, maintaining assets and adhering to regulatory standards, a number of water companies are shifting their business focus from operations to the maintenance of water assets in order to achieve greater productivity and profitability.
Essentials of M & R
From service reservoirs and water towers in the water supply process to storm water tanks and support chambers in wastewater treatment, most water-retaining structures are constructed from reinforced concrete. Regular maintenance and repair of these structures is vital, as chemical and mechanical influences can severely degrade concrete over time and cause interruption to water transmission, poor water quality and compromised structural integrity.
Specialty repair materials and cementitious coatings can help restore the original design life of water assets while ensuring optimal water quality and environmental sustainability. With many product options available, owners should make their selections based on a manufacturer’s test data and proven in-service track records backed by independent approvals, along with the expertise of technical staff who can recommend appropriate systems that provide a convenient and compliant, single-source solution.
Maintaining environmental sustainability is critical, and engineered mortars and cementitious coatings such as water-based, ultra-low-odor and solvent-free formulas can make all the difference — even when facilities must remain in operation during installation. Cementitious polymer-modified coatings and mortars — which provide rapid cure and faster return to service — are also ideal for direct application to prepared surfaces.
Reinforced Concrete Deterioration
Deterioration is caused by a number of chemical and physical influences, such as attack from soft water. Intercrete technologies, developed by AkzoNobel, incorporate materials like pozzolans and microsilica to boost resistance to soft-water attack. Adding polymers to select formulas also enhances the protective film on surfaces, offering additional chemical and physical resistance. Following are types of damage and the products that address them.
Intercrete 4841, a two-component water-based cementitious modified polymer coating, can be used in precast and in-situ structures to form a hard, highly alkaline barrier that protects concrete from aggressive acid gases, moisture and chlorides — while increasing asset lifecycles by up to 29 years.
Water seepage that occurs through construction joints and cracks can lead to leaching, corrosion, chemical attack, freeze/thaw damage and, ultimately, leakage of fluids either into or out of a facility. The certified Intercrete4872 bandage system is solvent-free with 600-percent elongation and achieves excellent bond when anchored directly onto an environmentally friendly cementitious coating.
Erosion to concrete is a problem in sewerage systems. While normal domestic sewage is slightly alkaline and doesn’t attack concrete directly, the real culprit behind erosion is bacteria-causing sulphuric acids that proliferate as changes to sewage occur. Intercrete4840 is a two-component, water-based coating that harnesses thermoplastic polymers and epoxy resins to create a tough, protective barrier to chemical and abrasion attack. The coating can be applied without a primer and is ideal for use in digester tanks where severe conditions are common.
Physical damage and substrate cracks can greatly affect the structural integrity and durability of concrete. Intercrete 4802 fast-cure repair mortar, based on a micro-fine Portland cement modified with sulpho-aluminate, has been successfully used for chemical and abrasion resistance and rapid return to service.
Carbonation breaks down the alkaline environment surrounding steel reinforcement and creates a problem for untreated concrete exposed to weather. High-performance decorative coatings such as Intercrete4890, are a cost-effective solution for protection against carbon dioxide, with a service life in excess of 10 years before first major maintenance.
The industry shift toward asset maintenance versus new construction is an important key to growing productivity and profitability. With the support of reputable coatings suppliers, investments in advanced, cost-effective coating technologies can help water companies protect water assets, while extending service life and increasing competitiveness.