Determination of the bitumen content in asphalt concrete using a neutron reflection method

A neutron physical method for the fast, nondestructive determination of the bitumen content in asphalt concrete has been developed. The determination is performed on cylindrical asphalt concrete samples containing desiccated rubble matrix. Using samples of ～1000 g and measuring times of 20 min, the reproducibility of the bitumen determination is ±0.15 w%, the sensitivity is 3·10^?3 g/g.