A durable concrete is one that performs satisfactory under the expected/anticipated exposure conditions for stipulated life of structure.
With the increase of concrete permeability, water and salt enters and it gets corrosion and incase of freezing of water it expands. permeability is most important factor which effect the durability of concrete in the following ways:
- It permit the chemical salt to enter into the concrete along with water.
- Frost Action
- Corrosion of Reinforcement.
- If water content increases, capillary water also increases, losses increase, voids increase and result increase of permeability.
- Curing, homogeneous mix
- Capillary voids are responsible for permeability.
Freezing and thawing of water is called frost action. Freezing of water inside of concrete increases volume and it developed cracks results decrease durability.
Due to sulphate attack concrete get expands and creates the void.
In carbonation, with reaction CO2 , decreases the permeability results decrease of durability.
Due to cracking of concrete, it decreases the durability of concrete because concrete is heterogeneous material and cracks also developed by thermal effect because concrete is heterogeneous material.
In sewage the crawn corrosion due to H2S which decrease durability. To enhance durability, we provide the cover as per exposure condition.
