粗集料针片状含量对沥青混合料结构影响

To investigate the reasons of different performance of asphalt mixture, volume index and structural parameters were measured in asphalt mixtures with different flat and elongated particles content. Void ratio of asphalt mixture was calculated based on industrial CT scanning and image processing technology, and color scale was used to mark the void structure. The parameters such as area, aspect ratio-AR ₁ and AR ₂ , mean value of spindle deflection angle, particle trend parameter-Δ and angularity were adopted to evaluate the structural characteristics of asphalt mixture. Results show that with the increase of flat and elongated particles, the volume density of asphalt mixture decreases and the porosity increases, and the void ratio calculated by industrial CT is larger than the measured. Macro-pore structure is mainly distributed in the middle and lower part of the specimens, but the voids at the top of the specimens are smaller. With the increase of the flat and elongated particles content in mixture, the aspect ratio expectation of particles-AR ₁ , AR ₂ and angularity expectation increases, and the cross section area of coarse aggregate particle decreases, but the influences on the mean deviation of deflection angle and grain trend are not obvious.