Prevention is always better than cure. Therefore proper design, planning and execution apart from proper control at every stage of construction is essential.
Porous materials, which shrink when dry, should be avoided. Bricks should be exposed for 2-3 weeks after burning and thoroughly soaked before being used in structures.
Fine sand, clay and silt should not be used.
In mass concreting, the heat of hydration should be controlled.
The use of heavy cement mortar, which has high drying shrinkage, should be avoided.
Shrinkage cracks can be significantly reduced by keeping the water to cement ratio to a minimum.
Large spans of slabs and windows should be avoided.
The foundation layer should be well prepared to avoid segregation of foundations. Foundations suitable for the type of soil and its bearing capacity should be adopted.
It is important to ensure that the soil is free of organic matter, bricks, debris etc.
Masonry and concrete should be properly treated.
In RCC framed structures, panel walls should be constructed from top to bottom.
Joints for movement should be provided as per standard especially on change of directions.
Plastering of panels and partitions should be delayed as long as possible while plastering of concrete should be done as soon as possible.
Adequate length of bearing should be provided for lintels to avoid cracks due to stress concentration.
Concrete in marine environments has to be compacted with sufficient cover thickness to avoid corrosion of steel.
Varying loading on the foundation should be avoided during construction.
Roots of trees removed for construction should be dried before starting construction.
Extreme care must be taken to avoid entrapped air and material segregation in the concrete. To achieve these, it must be ensured that the concrete mix has good workability and cohesion.
Before tampering with or modifying concrete or masonry structures (to extend, modify or even provide embedded service conduits for electrical, water and drainage lines) all aspects must be considered.
Admixed cement, minerals and chemical admixtures etc. play an important role in durability and hence their use should be encouraged. Waterproofing agents can be mixed with roofing concrete.
Failures are mainly due to ignorance, carelessness, greed and negligence. Therefore, extreme care should be taken in dealing with all the factors mentioned above.
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