Roads · measured in cum
Measuring bituminous course for RA bills
Bituminous courses are measured by compacted volume or by area for thin courses, as the BOQ states, with the bitumen content paid as the contract specifies.
Unit of measurement
Bituminous courses (DBM and BC) is measured in cum. Bituminous courses are measured by compacted volume or by area for thin courses, as the BOQ states, with the bitumen content paid as the contract specifies.
The BOQ item description decides the unit and what the rate includes. Where the BOQ and this guide differ, the BOQ and the contract's mode of measurement win.
What is measured
- Length of each stretch between chainages.
- Width of the laid course from the cross-section.
- Compacted thickness from levels or cores at the frequency the contract specifies.
- Bitumen content, where the contract pays bitumen separately or adjusts for variation in it.
Standard deductions
- Thickness laid above the design is not paid unless ordered.
- Areas over manholes and structures are taken out where significant.
- Prime coat and tack coat are measured in sqm under their own items, as per the contract's specification.
Worked example
MIDC internal road, dense bituminous macadam (DBM) 50 mm compacted, width 7.00 m widening to 7.60 m at the junction.
| Location | Nos | L | B | D | Qty (cum) |
|---|---|---|---|---|---|
| Ch 0+000 to 0+250 | 1 | 250.00 | 7.00 | 0.050 | 87.50 |
| Ch 0+250 to 0+500 | 1 | 250.00 | 7.00 | 0.050 | 87.50 |
| Ch 0+500 to 0+620 | 1 | 120.00 | 7.60 | 0.050 | 45.60 |
| Total | 220.60 |
Row by row: Ch 0+000 to 0+250, 1 x 250 x 7 x 0.05 = 87.50; Ch 0+250 to 0+500, 1 x 250 x 7 x 0.05 = 87.50; Ch 0+500 to 0+620, 1 x 120 x 7.6 x 0.05 = 45.60.
Total: 87.50 plus 87.50 plus 45.60 = 220.60 cum. Deductions are entered with negative nos, so they reduce the total in the same column.
Common disputes
- Thickness is claimed as designed while cores show less.
- DBM is billed in MT from plant tickets when the BOQ unit is cum.
- Tack coat is left out of the bill or billed twice.
Recording it in Tatha Vastu
Core results and level sheets are attached to each stretch. If the BOQ unit is MT, the entry takes plant ticket weights instead of dimensions, and the app checks the unit against the BOQ.
Approved entries are locked, and a correction becomes a new version with its reason. See the measurement book, or use the measurement sheet template if you still keep the register in Excel.
Is DBM measured in cum or MT?
Either, depending on the BOQ. Measure in the BOQ unit and keep the other figure as a check.
How is thickness checked?
By levels or cores at the frequency the specification sets.
Are prime coat and tack coat separate?
Usually yes, in sqm under their own items.