Quality control and quality acceptance of asphalt is mostly based on laboratory test results of samples taken from production or from the final pavement.
Generally, these tests represent only a small area of the work that has been done. However, the taking of many of these samples exposes technicians to relatively high risks in their working environment, that can be reduced if some of the more advanced solutions, mentioned here, are used. Many of these solutions (e.g. continuous compaction control, GPR, Thermal Mapping, etc.) also allow to get a more detailed and accurate picture of the quality of the pavement.
In the field of roads inspection, new devices, such as the Fast Falling Weight Deflectometer (FFWD) are designed to impart a load pulse to the pavement surface simulating the load produced by a moving vehicle. As they have no hydraulics, they are 5 times faster per drop than original FWD systems. Consequently, 75% more test points per hour or 45% less traffic exposure are produced. The load pulse is measured by load cells with resolutions up to 0.1 kPa, and the pavement response is recorded with resolutions up to 0.1μm.
Post processing software can be used to back-calculate the pavement layer moduli based on the impact load and surface deflection basin. The results can effectively be used for the evaluation of pavement structural condition and overlay design based on empirical or mechanistic-empirical pavement design guides.
At a different level, other solutions integrate rolling weight deflectometer systems (RWD), being able to collect simultaneously structural and functional data, identifying exactly the same critical areas on the pavement as Falling Weight Deflectometer systems. These tools can work at high speed, by following conventional road traffic, and collect continuous data from the entire pavement length. Consequently, the cost per km also reduce significantly.
In addition, to ensure consistency in the data over long terms, highly accurate calibration techniques based on integrated linear actuation systems for scanning a reference surface with zero deflection, have been developed, allowing the onboard calibration within a few minutes. This allows for fast and frequent calibration, which improves both accuracy and consistency in the data.
Representation of smart road surveying and inspection