(a) Engineering Considerations of Weathering are as follows –

i). Weathering is an important aspect from civil engineering point of view because all the civil structures are constructed using stone masonry and concrete work.

ii). Most important constitute material is stone which should be strong, tough, sound and hard. So the Quality of the stone depends upon the weathering condition of the available rock. The Weathered stone has to be avoided as their strength is low and unsound.

iii). The structures should be constructed on the good, strong and unweathered rock surface. Thus, the extent of weathering is important criteria for the site selection especially in case of high rise building, sea shore structures, tunnels, dams as the process of weathering weaken the strength of the rocks or soil.

iv). The architect and interior designers uses the marbles, granites for the ornamental work for the interior as well as the surface exposed to atmosphere. In that case, it is necessary to determine their suitability from the environment point of view as these stones are usually affected by chemical weathering agents like rains, temperature etc. and there is a chance to more porosity like honeycomb resulting in the loss of strength, durability, appearance and life.

(b) Different types of weathering.

i). Mechanical Weathering

• Frost Wedging or Freeze-Thaw

• Thermal Expansion and Contraction

• Rock Abrasion

• Unloading and Exfoliation

• Gravitational Impact

ii). Chemical Weathering

• Oxidation

• Hydration

• Carbonation

• Solution

iii). Spheroidal weathering

iv). Biological Weathering