• Iatroscan (picture: MK-6s TLC-FID Analyser) is a chromatographic analysis technique for the characterization of bituminous binders. This technique is based on the separation and quantification of the main components of bitumens (saturated compounds, aromatic fractions, resins, asphaltenes). This affords better understanding of the chemical composition of bitumens (origin, compatibility with polymer additives, etc.) and of modifications induced by external factors such as exposure to air (e.g., during the ageing of binders). The technique can also be used for the quantification of additives in (mastic) asphalt produced at a reduced temperature.
Iatroscan is complementary to other techniques for rheological or mechanical characterization available at BRRC.
Differential Scanning Calorimetry (DSC) is a calorimetric analysis technique for very accurate measurements of heat flows from and to materials within a wide range of temperatures (e.g., -80 °C to +500 °C). This makes it possible to determine the phase behaviour and the (in)stability of materials as a function of temperature (melting point or range, crystallization point, vitreous transition, specific heat, melting and crystallization heat, etc.).
DSC is complementary to other techniques for rheological or mechanical characterization available at BRRC.
The Belgian Road Research Centre has a falling weight deflectometer to measure the temporary deflection of roads under heavy traffic loads. A falling weight is dropped from a standing vehicle onto a metal disc laid on the road surface. A rubber interface on top of the metal disc damps the impact so as to simulate the passage of a heavily loaded wheel axle of a lorry. Nine sensors in the vicinity of the impact zone record the temporary deflection of the road surface. A deflection bowl can be determined from the measured data. The FWD is suitable for measurements on all types of pavement (from flexible to rigid) and for use on road networks. Usually one measurement is performed every 100 m. A single measurement takes less than two minutes.
The Belgian Road Research Centre has a footway profilometer to measure the longitudinal evenness of cycle tracks and other surfaces. A scooter with a trailer travels at a constant speed of 20 km/h on the surface to be surveyed. Using a laser and an accelerometer, the distance between the trailer and the road surface is recorded every 3 cm. The GPS coordinates and the distance travelled are recorded as well. From the measured longitudinal profile is possible to calculate the coefficient of evenness (for wavelengths of 0.5 m and 2.5 m) or other indicators of evenness.
Various types of asphalt mixture are used on our road network. Their compositions have to comply with performance criteria set in the tender specifications of the various road-managing authorities. Performance tests are used to check this compliance. One of these tests is the two-point bending test (picture: new device at BRRC) on trapezoidal specimens, to determine the rigidity modulus and investigate resistance to fatigue.