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
The Ultrasonic Pulse Velocity (UPV) test uses the time of travel of an induced wave to assess concrete quality. Key parameters given are:
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:
$V \approx 3.33 \text{ km/s}$
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.
In one litre of paint, volume of solid pigment and volume of non-volatile binder are 400 cc and 600 cc respectively. The Pigment Volume Concentration number of the paint is_______