Velocity (km/s) – cross probing Concrete quality grading Above 4.4 Excellent 3.75 – 4.4 Good 3.0 – 3.75 Doubtful Less than 3.0 Poor
UPV Test: Problem Setup
The Ultrasonic Pulse Velocity (UPV) test uses the time of travel of an induced wave to assess concrete quality. Key parameters given are:
- Distance between transducers, $L = 600 \text{ mm} = 0.6 \text{ m}$
- Time of travel, $t = 0.18 \text{ milliseconds} = 0.18 \times 10^{-3} \text{ s}$
- Test Method: Direct transmission as per IS 516 (Part 5/Section 1): 2018
UPV Test: Velocity Calculation
The pulse velocity ($V$) is calculated using the formula:
$V = \frac{L}{t}$
Substituting the given values:
$V = \frac{0.6 \text{ m}}{0.18 \times 10^{-3} \text{ s}}$
$V = \frac{0.6}{0.00018} \text{ m/s}$
$V \approx 3333.33 \text{ m/s}$
Converting the velocity to km/s:
$V \approx 3.33 \text{ km/s}$
UPV Test: Concrete Quality Grading
The calculated velocity is compared against the standard grading table provided in IS 516 (Part 5/Section 1): 2018.
| Velocity (km/s) | Concrete quality grading |
|---|---|
| Above 4.4 | Excellent |
| 3.75 – 4.4 | Good |
| 3.0 – 3.75 | Doubtful |
| Less than 3.0 | Poor |
The calculated velocity $V \approx 3.33 \text{ km/s}$ falls within the range of 3.0 – 3.75 km/s.
Therefore, based on the UPV test results, the concrete quality grading is Doubtful.
Important Questions from Building Material Characteristics
- As per the CPWD Specifications (2019), the material used for cleaning marble flooring after polishing is ______
- Select the statement(s) which are NOT correct with respect to burnt clay bricks.
- Bulking of sand is highest in
- The most important property of concrete in its fresh state is
- Assuming full compaction, strength of concrete is inversely proportional to
