6. LPC Bituminous Mixtures Design Guide, Sept 2007. - Aapaq.org

LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.3 Stiffness modulus test4.3.1 Experimental objective and procedureThe French mix design method relies on the laboratory determination of variouscharacteristics that allow predicting the in situ performance of bituminous materials,An LPC research project (CH 15: "Design of hot asphalt mixes") was thus undertakento respond to such questions. This program purposely focused on pavementstructure materials (primarily asphalt concrete for base course (AC-GB grave-bitume)and AC-EME high-modulus asphalt concrete mixes) in addressing, to the greatestextent possible, the main categories of materials used in road and highwaystructures, along with a wide range of aggregate origins.In particular, it was sought to characterize the variations in stiffness modulusobtained in the field. To proceed, some 20 extraction sites were determined in thefield, distributed over the entire length of the jobsite (approximately 10 km). At eachsite, two core samples 150 mm and 300 mm in diameter were produced. The150 mm samples yielded prismatic specimens for determining the direct tensilemodulus, In each of the 300-mm diameter samples, 3 trapezoidal specimens wereextracted in order to derive the complex modulus. The identification of 3 individualresults at any single point served to estimate local variability.Field values were then compared with laboratory values on materials produced usingthe worksite formulation and components.Figure 35: In situ core samplingFigure 36: In situ sawing- 136 -