CRACKS PREVENTION OF BUILDING

CAUSES AND PREVENTION OF CRACKS IN BUILDINGS

1. INTORDUCTION


Cracks in buildings are of common occurrence.

A building component develops cracks whenever stress in the component exceeds its strength.


Stress within a structural component may result from external forces applied to it, including dead loads, live loads, wind or seismic pressures,
or from the settlement of foundations.

& it could be induced internally due to thermal movements, moisture changes, chemical action, etc

2. Cracks could be broadly classified as structural or non-structural.

Structural cracks are those
Which are due to incorrect design.
Faulty construction or overloading


Non-structural cracks are mostly due to internally induced stresses in building materials

Non-structural cracks may, because of

Moisture change
• Thermal movement
• Elastic deformation
• Creep
• Chemical reaction
• Foundation movement & settlement of soil
• Growth of vegetation


3. CLASIFICATION OF CRACKS WITH WIDTH

Cracks May Visible vary in width
Depending upon the crack width cracks are classified as:
First is Thin crack – it is less than 1 mm in width,
Second is Medium crack – it is 1mm to 2mm in width,
Third is Wide crack – it is more than 2 mm in width.
Fourth is Crazing - Occurrence of closely spaced fine cracks at the surface of a material is called crazing



4. COMMON CRACK PATTERNS IN BUILDINGS

The commonly observed crack pattern in building can be group as,
Cracks in:
• Walls,
• RCC members,
• Renderings and plasters,
• Concrete and terrazzo floors,
And • Roof terrace

5. Types of Foundation Cracks

1. Vertical Cracks:-
These types of cracks occur due to the oil settlement and create a lot of pressure on the wall, leading to cracking.

2. Horizontal Cracks:-
These cracks are formed when horizontal pressure is exerted against the wall from the outside.

3. Stair Step Cracks:-
These types of cracks attack mortar joints between individual blocks due to solid pressure or settlement. These cracks run through the wall and form a stair-step pattern.

6. MEASURES FOR PREVENTION OF CRACKS
Measures for prevention of cracks could be broadly classified under the following

1. Regular Maintenance & Repair
Regular maintenance & repair of the building’s structural components can help prevent cracks from developing or worsening.

1. Crack sealing:
Crack sealing is a repair method that involves filling a material, such as chemical material with appropriate mix into the crack to seal it and prevent further damage

2. Crack Injection:
Crack injection is a repair method that involves injecting a material, such as epoxy, into the crack to seal it and prevent further damage.

3. Crack Stitching:
Crack stitching involves using metal plates or rods to stitch the crack back together. This method is effective for larger cracks that pose a structural risk.

4. Grouting:
Grouting involves filling the crack with a grout material to strengthen and stabilize the surrounding structure.
Apart from Regular Maintenance & Repair other Measures for prevention of cracks are

First is Choice of materials
Certain properties of building materials have very vital influence on cracking
It is necessary for the engineer/ architect to have proper knowledge and understanding of these properties

Second is Specifications for mortar and concrete;
Specifications of mortar and concrete have a very important role to play in regard to the incidence of cracking in buildings.

Third is Architectural & Structural design;
Proper Architectural & Structural design also play crucial role to avoid the cracks in building so it is important to take of all factor at time of design of building

Fourth is Foundation design;
Proper foundation design is essential to preventing settlement-related cracks. A strong, stable foundation will help distribute the weight of the building evenly, reducing the risk of settlement.
Fifth is Construction practices and techniques;