Cracks In Buildings – Thermal Crack

Preetham Builders one of the Best Builders in Madurai are developing Gated Community Luxury villas and flats.

This gated community ” BRINDAVAN HOMES ” is being developed in Kochadai Madurai, a fast developing area in Madurai.

With abundant water supply and green environments this gated community ” BRINDAVAN HOMES ” with individual buildings and Bungalows present a Resort like feelings.

Preetham Granite M.D addressed the gathering of engineers (Association of Madurai Civil Engineers) on Cracks in Buildings – Causes & Remedies at Hotel Weshtern Park ( 01.09.2016).

 

 Principal Causes of cracks in buildings

* Thermal stresses

* Elastic deformation

* Chemical Reaction

* Foundation movement and settlement of soil

* Moisture movement

* Vegetation

THERMAL CRACK:

Materials expand on heating and contract on cooling. But magnitude of variation depends on materials.

When there is restraint to movement of structure, internal stresses develop, resulting in cracks due to tensile or shear stresses.

Extreme cases, thermal stresses may exceed those of loading.

Thus thermal movement is most potent cause of cracking in buildings and needs serious attention.

Thermal coefficent of concrete is twice that of brickwork.

Drying shrinkage of concrete is 3 to 4 times that of brick masonry.

Immediate construction of parapet wall Parapet wall does not have self weight to counter shear force by concrete,

Thermal Movement

Thermal movement depends on number of factors.

Temperature variation,

Dimensions,

coefficient of thermal expansion,

Thermal conductivity.

Coefficient of thermal expansion Colour of surface Dark colours and highly textured materials have lower reflectivity than light coloured and soft texture.

Co efficient of thermal expansion

 

Heat reflectivity coefficient of common building materials

Heat Reflectivity

 

 

In load bearing brick work, horizontal cracks will appear as shown

Load Bearing BW

 

In framed structures, diagonal cracks will appear as shown

Framed Structures

 

Arching up and cracking of coping stones of a long garden wall

Crack

 

Horizontal crack at the base of brick masonry  parapet supported on a projecting RCC Slab

Horizontal Crack

 

Remedies :

slab be provided with adequate insulation, span should not be excessive,

Slip joint,