Water retaining bodies includes swimming pools, ponds, reservoirs, potable tanks, sumps, overhead tanks, STP, Dams etc. These structures are filled with water and are constantly under pressure depending on the depth of the structure also are in contact with different types of chemicals hence have higher chances of leakage. It is necessary that the waterproofing system can handle these factors.
Recommended Solution by Aquaseal –
1) Cementitious Coating System
A) Crystalline based Cementitious System (only positive side)- These systems are an active system. The crystalline system includes normal Portland cement, specially treated quartz, and a compound of active chemicals.
When applied to a concrete surface, the active chemicals react with moisture and the un hydrated cement particles to cause a catalytic reaction which generates an insoluble, crystalline structure. These crystals fill the pores and minor shrinkage cracks in the concrete to prevent any further water ingress (even under pressure).
However, the system will still allow the passage of vapour through the structure (i.e. the concrete will be able to “breathe”). Even after the concrete has cured, the system remains dormant in the concrete and will reactivate in the presence of moisture to seal capillary tracts and hairline cracks. In addition to waterproofing the structure, it also protects concrete against seawater, wastewater, aggressive ground water and many other aggressive chemical solutions.
The system is approved for use in contact with potable water, and is therefore suitable for use in water storage tanks, reservoirs, water treatment plants, etc.
Prior to application of these systems, the surface must be clean and sound as per checklist i.e., all joints, honeycombs and hollowness must be packed with crystalline/ repair mortar. Pressure grouting using PRAH (Permeability Reducing Admix for Hydrostatic Conditions) at all weak spots/zones. Angle fillet min 50*50mm must be made all along the corners using PMM. Bore packing must be done using non shrink grout like GP2. The surface must always be in SSD.
Post-treatment: The treated areas should be kept damp for a period of 10 days and must be protected against direct sun, wind, and frost, by covering with polyethylene sheeting, damp burlap or similar.
B) Polymer based Elastomeric Cementitious coating system (only positive side)-
Polymer based Elastomeric Cementitious coating systems are high performance elastomeric cementitious coating used for waterproofing and to protect atmospherically exposed reinforced concrete structures from attack by acid gases, chloride ions, oxygen & water.
These systems can be used on concrete, brick and block work substrates and is equally suitable for new and existing structures. The product is designed to reface and even out variations in concrete and masonry surfaces and bridge shrinkage cracks. It provides a seamless, flexible waterproof coating suitable for water tanks, reservoirs, drainage culverts basements and roofs. The product provides a tough durable water-resistant coating which can withstand light pedestrian traffic and has excellent weather resistance for exterior applications. These systems are preferred as an undercoat system as they are not UV stable.
Prior to application of these systems, the surface must be clean and sound as per checklist i.e., all joints, honeycombs and hollowness must be packed with PMM (Polymer Modified Mortar) /Non-Shrink repair mortar. Pressure grouting using PRAN (Permeability Reducing Admix for Non-Hydrostatic Conditions) at all weak spots/zones. Angle fillet min 50*50mm must be made all along the corners using PMM. Bore packing must be done using non shrink grout like GP2. Surface must be in SSD state.
2) Bitumen/epoxy based system (positive side only)- In special cases, for STP Tanks and potable water tanks with internal plaster, where the plaster cannot be removed in order to access the parent substrate, in such situations, and only if the plaster is sound, waterproofing can be performed over the plaster using these systems.