Q. Why do leakages occur in concrete structures?
Leakages occur because of variety of reasons; some of which are mentioned below :
1. Accumulation of water, which start penetrating the surface.
2. Poor quality and improper proportioning of concrete constituents that make concrete permeable.
3. Poor compaction of concrete, which leave a lot of air voids.
4. Construction joints at two different works like concrete and brick works, and discontinuity in concrete casting (joint at old concrete and new concrete) leading minute cracks, which facilitate water movement.
5. Other structural cracks because of loading conditions and failure of the structure to withstand those stresses.
6. Movement of water from bottom to top because of capillary action.
Q. How can leakages be avoided?
Following measures may be useful to avoid leakages:
1. Provide good drainage facility with correct gradient at the places where there are chances for water to accumulate.
2. Use good quality of materials with correct proportioning in concrete. For example, use of blended cement and use of less water in concrete can reduce permeability of the structure. Similarly, proper proportioning of materials would help concrete becoming uniformly packed and dense.
3. Proper compaction of concrete with immersion vibrator to make it void less.
4. Avoid construction joints becoming a weaker point for water to travel. Some proactive and treatment measures would be useful.
5. Proper structural design and execution of members, which results no cracks for water to percolate.
6. Proper damp proofing course required to avoid movement of ground and other water from bottom to top. Some useful methods are like applying bitumen, concrete construction etc. at plinth level.
7. Use of water proofing compounds for water retaining structures.
Q. Do we require adding water proofing materials in normal concrete construction?
Normal concrete construction should not require water proofing materials, if it is designed and constructed properly with good quality and workmanship.
Q. In what forms water proofing materials, available?
Water proofing materials are available in powder and liquid forms. It is advisable to buy water proofing materials of reputed companies.
Q. While repair of normal constructions to get rid of leakages or during construction of water retaining structures, what should be the doses of waterproofing admixtures or construction chemicals?
Always read the instructions of manufacturer in product catalogue or on the container/packet.
ACC's waterproofing compound "ACCOPROOF" is available in powder form and 1 Kg packets. For normal purposes, 1 Kg is required to be used with 50 Kg (1 bag) of cement.