a)

Accumulation of water, which start penetrating the surface.

b)

Poor quality and improper proportioning of concrete constituents that make concrete permeable.

c)

Poor compaction of concrete, which leave a lot of air voids.

d)

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.

e)

Other structural cracks because of loading conditions and failure of the structure to withstand those stresses.

f)

Movement of water from bottom to top because of capillary action.

a)

Provide good drainage facility with correct gradient at the places where there are chances for water to accumulate.

b)

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.

c)

Proper compaction of concrete with immersion vibrator to make it void less.

d)

Avoid construction joints becoming a weaker point for water to travel. Some proactive and treatment measures would be useful.

e)

Proper structural design and execution of members, which results no cracks for water to percolate.

f)

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.

g)

Use of water proofing compounds for water retaining structures.