Table of Contents

1.3.3 Data reporting

General

Data must be properly referenced in order to be meaningful for use in decision making processes. Accordingly, strength data must be reported using an established predefined location referencing system, such as the Roads and Maritime Roadloc system (RTA NSW 2002), although spatial location is starting to overshadow linear referencing systems.

Reports must clearly identify the lane surveyed and the direction of travel during the survey, as well as the date and weather conditions, and any impediment to the survey, or missing or invalid results and their cause (e.g. roadworks, lane change manoeuvres, obstacles on the road, etc.).

The precision of reported data should meet the minimum levels shown in Table 1.7.

Table 1.7: Minimum data precision levels for reporting FWD data

ParameterMinimum reporting precision
Impact peak load level1 kPa
Deflection sensors1 micron
Temperature1 °C

Precision is not the same as accuracy. Whilst Table 1.7 requires that deflection sensor readings be reported to a precision of 1 micron (μm), it is important to realise that individual readings are extremely unlikely to be accurate to this level of precision. By way of comparison, human hair width generally ranges from 20 μm (flaxen hair) to 180 μm (black hair).

Reporting falling weight deflectometer data

The data to be collected and reported for each test location should include the following:

  • location of the test point with regard to the client specified location reference system
  • target load level
  • impact peak load measured during the final (i.e. third) loading cycle
  • pavement deflection measured by each of the deflection sensors during the final loading cycle
  • normalised pavement deflections for each of the deflection sensors corresponding with the final loading cycle
  • ambient air temperature during the test, reported to, at least, the nearest 1 °C
  • pavement surface temperature during the test, reported to, at least, the nearest 1 °C.

Reporting traffic speed deflection data

The data to be collected and reported for each survey should include the following:

  • date/time of testing
  • testing speed
  • known test axle load to the nearest 0.1 tonne and its variation throughout testing to allow normalisation of dynamic load effects using load measuring sensors
  • impact peak load measured continuously
  • tyre pressure of the test axle tyres
  • location of the pavement road/section with regard to the client-specified location reference system, including start and end chainages of survey test runs, and locations of any reference or control points within the survey
  • test lane and direction of survey
  • normalised full deflection bowls estimated from Doppler laser velocities and the chainages or intervals at which they were estimated and reported using an Area Under the Curve (AUTC) approach (Muller & Roberts 2013)‘
  • ambient air temperature, reported to, at least, the nearest 1 °C (if measured)
  • pavement surface temperature, reported to, at least, the nearest 1 °C (if measured)
  • error or event flags and operator comments where applicable.

Reporting deflectograph data

The data to be collected and reported for each survey should include the following:

  • date/time of testing
  • known test axle load to the nearest 0.1 tonne
  • tyre pressure of the test axle tyres
  • location of the pavement road/section with regard to the client-specified location reference system, including start and end chainages of survey test runs, and locations of any reference or control points within the survey
  • test lane and direction of survey
  • deflection bowls measured and the chainages at which they were measured – as a minimum, maximum deflection and the curvature function must be reported
  • ambient air temperature, reported to, at least, the nearest 1 °C (if measured)
  • pavement surface temperature, reported to, at least, the nearest 1 °C (if measured)
  • pavement temperature at 30 mm depth, reported to, at least, the nearest 1 °C (if measured)
  • error or event flags and operator comments where applicable.

Reporting Benkelman Beam (BB) data

The BB is not as widely used as the FWD, TSD and DFG. Data reporting requirements will be similar to those for the DFG.