Visual Inspection

Visual inspection is the preliminary visit to the site and structure to assess the existing condition of the structure and to collect the relevant data, /documents and structural drawings of the structure. The non destructive and partially destructive methods to be adopted are evaluated for the particular structure based on visual inspection.

  • Reference location of the structure
  • General layout, plan and elevation of the structure
  • Photographs of the damage
  • Photographs of the site
  • Damage / Defect Identification

Type of Damage / Defect
  • Identification of damage in the structure
  • Avoid assumptions
  • Decision about non-destructive test

Pile Integrity Test

(As Per BIS - 14893)
With minimum interface with other site activities, the approximate pile length can be determined and the integrity of the pile can be assessed quickly. This test can be performed on any kind of concrete pile with minimum preparation, according to site condition.


Rebound Hammer Test

(As per ASTM C805, BS 1881 Part 202, BIS 13311-P2 )

  • In-situ testing to determine maximum compressive strength at near surface in concrete structure
  • Quality control for pre-fabricated concrete elements, like slab, wall and pile etc.
  • Identify the extent of damage due to fire, chemical, corrosion, etc.

Average Rebound No.
Quality of Surface hardness/Strength
> 0
Good Hard Layer

A general guide between the surface hardness and the rebound number for N-type hammer, is given above. Ref : SERC Conducted advanced course on damage assessment and rehabilitation of distressed concrete structures - Dec 1996.

Ultrasonic Pulse Velocity Test

(As per ASTM-C597, BS-1887-203, BS-6089, BIS-516 (Part 5 – Sec I)
To assess the condition with regard to homogeneity, integrity, identification of presence of voids, cracks and honeycomb in concrete.

Velocity Criterion for Concrete Quality Grading

Pulse Velocity by cross probing (Km/sec)
Concrete Quality Grading
Above 4.40
3.75 to 4.40
3.0 to 3.75
Below 3.0

The analysis and interpretation of test results will be on the base of above guidelines.

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Ultrasonic Pulse Velocity Contour Analysis As per BIS-516 (Part 5 - Sec1)


Impact Echo Testing

(As Per BIS - 14893)
The impact echo testing technique is used to test the plain, reinforced and pre-stressed concrete whether it is precast or cast in-suit. The data is used to determine

  • The homogeneity of the concrete
  • The presence of anomaly such as void, debonding, cracks and other imperfections
  • Change in the concrete quality (modulus) in relation to specification
  • The thickness of concrete member such as slab, beam, column or footing, etc.

Profometer (Covermeter) Scan

(As per BS 1881-204, ACI 312-83)
Quality Assurance
To locate embedded steel reinforcement measure depth of cover and estimate diameter of reinforcement bars, including spacing of bars.
Condition Surveys
Check actual cover thickness for life prediction.
Nominal Concrete Cover to Meet Durability Requirements (As per BIS - 456:2000)

Nominal Cover in Concrete in mm not Less then
Very Severe

Half Cell Potential Mapping and Corrosion Risk

(As per ASTM-C876)
Corrosion mapping is very useful in identifying corrosion tendency in concrete structure before it develops further to cause the visible damage to the structure such as crack or surface deterioration.
The significance of corrosion in steel reinforcement can be assessed using half cell potential measurement. ASTM C876 gives the following interpretation with contour analysis.
Half-Cell Potential Measurement Acceptable Limit

Probability of Corrosion
Ecarr (Vsca/CuSO4)
Greater than 95%
More Negative than - 350 mV
Approx 50%
Between - 200 mV and - 350 mV

Half Cell Potential Data Contour Analysis As Per ASTM C 876


Resistivity Measurement

(As per BS 1881:201)

  • Collected Resistivity Measurement date on reinforced Corrosion at site will give corrosion activity.
  • Test for saturate resistivity to assess the corrosion

Used to monitor change in exposure

  • Test a structure over a period to determine the seasonal changes.
  • Make allowances for instant changes due to corrosion level in concrete.

Resistivity Ohm-cm
Likelihood of Corrosion
< 5000
Very High
5000 - 10000
10000 - 20000
Low / Moderate
> 20000

Linear Polarization Test

To Determination the Corrosion Rate

Corrosion Current Density
Above 15 A/cm2
High corrosion rate
Between 5 & 15 A/cm2
Moderate corrosion rate
Between 1 & 5 A/cm2
Low corrosion rate
Below 1 A/cm2
Negligible corrosion rate

According to the experience from the laboratory and in situ tests, the above criteria are recommended by the Manufactures the equipment.


Chemical Analysis for

  • Chloride Content
  • Sulphate Content
  • Carbonation Depth
  • pH
  • ASR Diagnosis
  • Acid Attack Diagnosis
  • X-ray diffraction (XRD)
  • X-ray Fluorescence (XRF)

Concrete Coating Thickness Gauge

Concrete coatings are common in industrial and commercial building. Structures are specified for a minimum coating thickness. This ultrasonic device provides a non-destructive means for determining coating thickness.

Rapid Chloride Permeability Test (RCPT)

(As per ASTM C 1202, AASHTO T 259)
Chloride diffusion is detrimental in as much as direct corrosion by pitting on steel and electro-chemical process of corrosion due to reduction of the passive layer around steel. Rapid chloride penetration test (RCPT) is a quick indicator of permeability. The values in coloumbs indicate the corrosion potential in terms of CL - permeability.

Rating on Permeability
Reading in Coulombs
> 4000
2000 - 4000
1000 - 2000
100 - 1000
Very Low
< 100
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Core Sampling and Compression Test

(As per BIS-516 (Part - 4), 456, SP 24, ASTM C39, C42 AASHTO T22)
Concrete strength" typically means the compressive strength of concrete, depends on a number of factors, such as

  • Porosity (which in turn depends on compaction, water/cement ratio, air entrainment and other factors relating to voids)
  • Aggregate grading (particle size distribution of the aggregate)
  • Age of concrete
  • Aggregate-paste bond
  • Aggregate strength
  • Type of Admixture
  • Cement content and strength
  • Sand content
  • Curing method

Concrete Petrographic Studies

(As per ASTM - C856, C457, C1084, C294, C295, C642, C157)
This study covers the following parameters

  • Nature of coarse and fine aggregates
  • Mineral contaminants
  • Organic contaminants
  • Volume fractions coarse aggregate, fine
  • aggregate, paste, air
  • Air void system parameters
  • ASR
  • Sulphate attack
  • Carbonation
  • Incomplete hydration
  • Pozzolanic admixtures silica fume, fly ash
  • Granulated blast furnace slag
  • Finishing and curing procedures
  • Incomplete hydration
  • Concrete mixing
  • Placement and compaction
  • Segregation/over compaction
  • Re-tempering
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Recommended Limits of Total Chloride and Sulphate content of Concrete

(As Per BIS 456-2000)

Maximum Sulphate (SO4) contents (% by weight of Cement)
Maximum total Acid Soluble Chloride Content Expressed as kg/m3 of Concrete
Type of Concrete
The total water soluble sulphate content of the concrete mix, expressed as SO4 should not exceed 4% of mass of the cement in the mix.
Reinforced concrete
Un-reinforced concrete

Ground Penetrating Radar System

(As Per ASTM D4748)
Studie in this systems is intended

  • To inspect floors, decks, slabs, tunnels, balconies, garages, etc.
  • To locate rebars, tension cables, conduits, voids, PVC Pipes and measure slab thickness.
  • To detect and map the relative concrete condition for rehabilitation planning.
  • To faster, safer and lower cost than radiography (x-ray)
  • To only single-sided access needed in GPRS
  • To easily and safely locate the embedment's within concrete structures prior to drilling and core cutting.

Bond Test

(As Per ASTM C1404)
To determine the surface strength of concrete

  • Strength assessment prior to repair and rehabilitation

To measure adhesive strength of

  • Coatings
  • Carbon Fibre

To check the overlays

  • Shotcrete
  • Toppings
  • Repaired Materials

Infrared Thermography

(As Per ASTM - D4788)
This study in intended

  • To predict air leaks in the building envelope (energy saving)
  • To identify the presence of moisture that leads to mold and mildew damage (prevent illness)
  • To identify potential electrical fire hazards (life saving)
  • To identify roof damage (Replace or Repair)
  • To assess the overall thermal condition assessment of the structure

Vibration Analysis

As Per BS 2011:Part 2.1Ea, 3015, 7129, ISO 2631-2, 3010, 4356, DIN 4149 - 1, 4150-1, 4150-3
Construction activities are expected to affect buildings and building occupants in all sectors where the distances from vibration source to receiver are sufficiently large to effectively mitigate the effects. The sectors in which vibration effects are most likely are those where operations are undertaken in close proximity to sensitive receivers and/or involve high-vibration activities (vibratory rollers, piling and blasting)
The key vibration sources for the construction phase are anticipated to be:

  • Building Vibration
  • Blasting
  • Vibration rollers for base course and road surfacing
  • Piling and bridge abutments, diaphragm wall construction, port construction and retaining.
  • Rock breaking
  • Tunneling equipment 'open face excavation'
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Building Vibration Testing

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Soil Investigation

Field Work

  • Boring
  • Shell and Auger Boring by Both Manual and Mechanical Winch
  • Wash Boring by DMC Method
  • Rock Boring

Field Test

  • Standard Penetration Test
  • Dynamic Cone Penetration Test
  • Static Cone Penetration Test
  • Plate Load Test
  • Block Vibration Test
  • Electrical Resistivity Test


Index Property of Soil

  • Natural Moisture Content
  • Liquid Limit, Plastic Limit and Shrinkage Limit
  • Bulk Density and Dry Density
  • Particle Size Distribution

Shear Strength Parameters of Soil

  • Unconfined Test
  • Triaxial Test with and without Pore water Pressure
  • Direct Box Shear Test
  • Vane Shear Test

Consolidation Parameter Test
C.B.R. Test
Permeability Test

Data Analysis and Recommendation
Analysis of all the data collected from field and laboratory tests. Complete report be submitted with our expertise comments based on guidelines for selection of foundation type, size, depth, bearing capacities and economic construction procedures.