Nanotechnology-Based Waterproofing Compounds
These waterproofing compounds can be used to treat practically any material widely used in construction. This includes cement sheets, concrete, bricks, sandstone, granite, marble, limestone, plaster, and other natural stones. Nanotechnology-based Monomeric compounds are commonly used in water-proofing products.
Less than 6 to 8 nm is the size of the molecule. They can quickly and easily go within the substrates' pores. The molecules inside the substrate flow through the pores and branches because of their small size. They are typically applied as a water solution, though the producer may optionally recommend just using another solvent.
Such waterproofing compounds are found to be very efficient in covering the surface and provide deep penetration as below:
They will stand hydraulic pressure generated by high wind driven rains,
They give protection against micro cracks,
They also protect the structures from water damage after abrasion due to heavy traffic or natural weathering of the surface,
Protects the reinforcement from corrosion,
Protection at the joints:
The joints of a structure are comparatively small but crucial and prone to damage. Normally, joints experience greater stress than other structures do. Through the porous nature of the joint components, the thick concentration of reinforcement, difficult shuttering, and inferior execution, water can easily leak in.
Water swells the joints and it de-swells whenever water leaves the joints. The swelling and deswelling process generates void sand and develops cracks. Waterproofing treatment of joints prevents water penetration into the joints thus avoiding swelling and the deswelling process.
Protection of structures after the cracks are formed:
There are two types of concrete: concrete that is cracked and concrete that has the potential to crack. When exposed to wetting and drying conditions, concrete will expand and contract.
If the stress associated with these volume changes exceeds the tensile capacity of the concrete, cracks will form. Such cracks are referred to as shrinkage cracks. Besides this, normal RCC is also designed as a cracked section, in order to transfer tensile stresses to reinforcement bars.
Potential Cracks are also expected to develop in the joint area as it acts as a "pressure release valve". At the junction, members of different thickness are joined together, for example beam & slab junction where slab of less thickness is joined to a beam.
This allows a crack to form along a straight line within the joint since the thin section provides a path with less resistance than a thicker section. These micro-cracks are normally 0.1 to 0.2 mm wide and 2-3 mm deep. Nanotechnology-based hydrophobic waterproofing compound penetrates inside the concrete structures and protects it from water infiltration.
Prevention of surface-developed black spots on new structures:
The black spots are remains of biological growth (Mildew, Fungi). Concrete surface is very coarse and porous. Therefore concrete traps moisture in these pores and biological growth occurs where moisture and food are available. Concrete and plaster surfaces retain moisture very effectively and promote fungus growth.
These biological growths die and leave organic residue (black spots). This residue becomes food for the next generation. These vicious cycles continue and cover the entire surface within a few monsoon cycles.
These stains are generally removed by a high-pressure water jet and 3-5% solution of bleach . First, the surface is cleaned by high-pressure water jets to loosen the residue.
This biological growth can also be eliminated by removing one of the important components, i.e. moisture. The use of nanotechnology-based waterproofing compounds changes the surface characteristics from hydrophilic to hydrophobic thereby preventing moisture accumulation in the pores. Hence formation and growth of fungus or mold is prevented for a longer period.