QA / QC

Ultrasonic Pulse Velocity (UPV) Test

Non-destructive test gauging concrete quality + uniformity from sound-wave speed

Also calledultrasonic pulse velocityUPV testpulse velocity testconcrete ultrasonic testNDT concrete velocity
Related on InfraLens
CODES
IS 13311
Definition

The Ultrasonic Pulse Velocity test, per IS 13311 Part 1, passes an ultrasonic pulse (~50-54 kHz) through concrete between a transmitting and receiving transducer and measures the transit time; dividing path length by time gives the pulse velocity (km/s). A denser, sounder, void-free concrete transmits the pulse faster, so velocity is a non-destructive index of quality, uniformity and the presence of cracks, honeycombing or deterioration.

Indicative IS 13311 grading: > 4.5 km/s 'excellent', 3.5-4.5 'good', 3.0-3.5 'medium', < 3.0 'doubtful'. It is used for direct, semi-direct or indirect transmission and is most powerful for comparative + uniformity surveys and crack-depth estimation rather than absolute strength. UPV is routinely combined with the rebound hammer (the SonReb method) and calibrated against core tests within an IS 456 Cl. 17 investigation.

Where used
  • Concrete-quality + uniformity surveys
  • Crack-depth + void/honeycomb detection
  • IS 456 Cl. 17 distress investigation (with cores)
  • Monitoring deterioration of existing structures
  • SonReb combined NDT strength estimation
Acceptance / threshold
Per IS 13311 Part 1 velocity bands (excellent >4.5, good 3.5-4.5, medium 3.0-3.5, doubtful <3.0 km/s); used qualitatively + correlated to cores for strength inference under IS 456 Cl. 17.
Frequently asked
What does ultrasonic pulse velocity indicate?
The speed of an ultrasonic pulse through concrete — higher velocity means denser, more uniform, sounder concrete. It detects voids, cracks and deterioration and grades overall quality per IS 13311 Part 1.
Can UPV alone give concrete strength?
Not reliably on its own — it is best for uniformity, defect detection and comparison. For strength it is combined with the rebound hammer (SonReb) and calibrated against core tests.
Related terms
Rebound Hammer Test
Non-destructive test for in-situ concrete strength — surface hardness measured via spring-loaded hammer.
Spalling of Concrete
Flaking/breaking off of concrete cover, often from rebar corrosion or fire
Half-Cell Potential Survey
Non-destructive electrochemical mapping of reinforcement corrosion probability
QA/QC Inspection
Quality assurance and control checklists/templates
Field Quality Plan (FQP)
Project-specific QC document covering all activities — test methods, acceptance criteria, sampling rate.
Split Tensile Strength
Indirect tensile strength of concrete from diametral splitting of a cylinder
Concrete Core Test
Drilled cylindrical core tested for in-situ concrete strength when cubes are in doubt
Flexural Strength of Concrete (Modulus of Rupture)
Tensile strength in bending from a beam test; governs pavement slab design
Non-Conformance Report (NCR)
Document raised when work fails to meet specifications. Includes root cause, corrective action, preventive action.
Non-Conformance Report (NCR)
Report for work not meeting specification