By
Shubham Sunil Malu
1.0 INTRODUCTION:
Cracking is one of the major issues in concrete. Since concrete has various physical and chemical properties it is prone to cracking. Its elimination is not possible totally but it can be restricted or reduced to a certain extent. Mostly, cracking goes on a microscopic scale and does not appear visibly as a fault. If the cracking goes on a macroscopic scale it can result in loss of strength, stability and durability. It can also cause decrease in sound insulation and overall efficiency besides affects aesthetics to a greater extent.
The main causes of cracking are as follows:
- Ageing – Carbonation
- Foundation problems
- Weathering Actions
- Improper or modified use of the structure
- Poor maintenance
- Progressive loading
- Deficiencies in design
- Poor quality of concrete material
- Improper concrete mix
- Movement of concrete arising from physical properties
- Poor workmanship and negligence
- Over trowelling and impermeable formwork
- Reduced continuity of the structural member
- Defects and errors in construction practices
- Improper structural repairs or modification
- Chemical attacks by Chlorides and Sulphates
- Differential thermal stress – Heat of hydration of cement