Today Man's shelters has changed from under the trees or in caves to skyscrapers to sub- terrain bunkers and complexes, all possible thanks to the discovery of reinforced cement concrete. The construction industry faces new challenges to make the structures stronger, sleeker, of sizes and shapes and at locations that defy imagination as well accompanied by challenges to make them economical, damp proof, decay-proof etc.
Concrete and other materials like bricks, blocks, etc are being used extensively right from the founding level below the surface level to the rooftop. Today admixtures, coatings, adhesives, sealants etc., form an integral part of all that goes into constructing a habitat or structure or a utility at various stages of construction.
Reasons for Intrusion of Water into Structure
- Accumulation of water, which start penetrating the surface.
- Poor quality and improper proportioning of concrete constituents that make concrete permeable.
- Poor compaction of concrete, which leave a lot of air voids.
- 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.
- Other structural cracks because of loading conditions and failure of the structure to withstand those stresses.
- Movement of water from bottom to top because of capillary action.