Building Diagnosis

Presented By:

Sawalkar Balaji

Building Diagnosis “Building diagnosis” is a process of data collection regarding conditions, detection and analysis of faults/abnormality/defects in building materials and fabrics. There are two stages of building diagnostics: Fault Detection: Determination of fault. Fault Diagnosis: Identification of fault. This process can be carried out by: Infrared Thermography.(IRT)UltrasoundRadarsLasers

Infrared Thermography: It’s a modern non-destructive method (NDT) for examination of non-renovated & redeveloped buildings. Infrared cameras are used to measure the temperature in interiors and exteriors of building.Its been used for last 30 years for building diagnosis in effective and economical manner.Principle: Its based on “Kirchoff Law of Thermal Radiation” Energy absorbed = Energy emitted(for perfect black body)

Infrared Camera

Any material continuously emits energy proportional to its surface temperature.

To obtain IR radiation heating of surface is necessary.

By estimating the temperature distribution over the surface the defect can be identified.It’s the only technology that allows the infrared radiation to be transformed in a visible image.

IR Absorbed= IR Emitted

Thermography Scanning system measure the temperature based on IR radiation emitted from heated surface without physical contact between them. The infrared cameras convert the emitted radiation

into 2-Dimentional (2D) picture consisting of different. shades of color.

2D picture of building

There are two types of thermograph:Active Thermography Passive Thermography

Active Thermography: The active thermograph is frequently chosen to examine the inside of a building, using an external source of IR radiation and these can be gained by means of external heating. It gives the information about interior structural elements.

Here the energy can be transferred to the object in two ways:

Lock-In Thermography: Here the energy is delivered

the to object in periodic way.

Pulse Thermography: Here the energy is delivered to the object in a single shot.

Passive Thermography: This method is used directly in the presence of solar radiation. It doesn’t require any external of heating .

Its used to examine exterior of building mainly for the diagnosis of historical building.Applications:

Used to access-. Roof leaks.

Thermal performances of building.(Temp.)

Passive Thermograph

Heat loss by conduction , convection , radiation.

Moisture present in exterior walls and roof can be detected.

Conduction: Heat transfer within the body.

Convection: Heat transfer from one body to other body.

Radiation: Energy transferred by thermally charged particles.

Hidden characteristics such as cavities , holes and structural changes in problematic areas.

Used for insulation inspection and reason for increasing moisture content in particular area.

Reasons for degradation of building structures.

To evaluate HVAC (Heating, Ventilation, Air-Conditioning).

Air leakage from glass doors , windows and sealing work

Cavities or Holes

Structural Changes

Sick Building Diagnosis: Its used to access mold growth on wet walls ,damages such as brick sprawling ,roof member corrosion ,Energy losses.

Energy losses

Heated floors can be easily identified and their length can be calculated.

Holes in concrete and water leakages in pipes can be determined.

Ultrasound : It’s a type of non- destructive (NDT) testing method commonly used to find flaws in materials and to measure the thickness of objects.

Its frequency ranges from 2-10Mhz.

Principle: Its based on the study of sound wave propagation through concrete materials and their velocity of propagation. (Echo) Echo

Applications:

Pulse velocity is used to determine: Homogenous nature Presence of voids Cracks Other Imperfections Used to detect objects & measure distances by echo.

A ultrasonic wave is sent into a material and depending on the velocity of propagating wave, echo the characteristics are determined.

Laser: A laser is a device that emits the light through a process of optical amplification based on stimulated emission of electromagnetic radiation.

Application:Diagnosis of historical monumentsIdentification of contaminated regions on the porous stone document

Used for cleaning monument by NDT

Golden temple

Radar: It has a transmitter which transmit radio waves called radar signals ,that get in contact with object then it get scattered and its received by receiver , later on they are amplified.

Application:

Types of traces on tall building can be identified without Scaffolding.

Thank you