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A large amount of soybean oil (20%–30% mass ratio of neat asphalt) was selected to partially replace petroleum asphalt. The high-temperature behavior of soybean oil bioasphalt was enhanced by polyphosphoric acid (PPA). Polyphosphoric acid/soybean oil composite modified asphalt (PSMA) was prepared. Temperature sweep, frequency sweep, multiple stress creep recovery, and bending beam rheometer tests were conducted to reveal the rheological behavior. Fourier infrared spectroscopy (FTIR), scanning electron microscope, and fluorescence microscope tests were carried out to reveal its microstructure characteristic. The results proved that polyphosphoric acid obviously increased the high-temperature properties of soybean oil bioasphalt. Compared with the neat asphalt at 0.1 kPa, the recovery rates of 20% bio/6% PPA, 25% bio/6% PPA, and 30% bio/6% PPA increased by 139.2%, 113.5%, and 86.4% respectively. PSMA was less sensitive to temperature and loading frequency, with remarkable elastic recovery and antirutting degeneration ability. PSMA could maintain excellent low-temperature crack resistance at −18°C. PSMA had better rheological properties when soybean oil and PPA were 20%–25% and 4%–6%, respectively. The FTIR tests verified that some new functional groups emerged in PSMA. There were evenly distributed fluorescent materials in the soybean oil bioasphalt under the fluorescence microscope. Under the modification effect of PPA, soybean oil and PPA could be evenly dispersed in PSMA. Laboratory tests verified the superior properties of bioasphalt with high content soybean oil. [ABSTRACT FROM AUTHOR]

Using sparse matrix for total focusing method (TFM) imaging can improve computational efficiency in non-destructive testing (NDT). In sparse matrix design, binary particle swarm optimisation (BPSO) and genetic algorithm (GA) often fall into local optimal solution, and the computational efficiency decreases significantly with the expansion of array scale. In this paper, a discrete war strategy optimisation (DWSO) is proposed to realise sparse array ultrasonic imaging. This method uses equidistant scatter mapping to real-number encode the array position and limit the search range. Then, the fitness function is constructed with low side lobe peak and narrow main lobe width to obtain the optimal array element distribution. Experiments on standard test block demonstrate the DWSO algorithm has a narrower main lobe width and lower side lobe peaks than BPSO and GA. The imaging time of the sparse array constructed by this algorithm is reduced by more than 65% compared with the full array. As array scale grows, the running time variation of the proposed method is reduced by 73.2% and 77.3% compared with GA and BPSO, which has good adaptability and provides theoretical support for real-time defect detection. [ABSTRACT FROM AUTHOR]

The performance and modification mechanism of Buton rock asphalt (BRA) modified asphalt were analyzed. The road performance of modified asphalt was observed and compared with SBS modified asphalt to confirm the modification mechanism. Four‐component test, and dynamic shear rheological tests were conducted to identify the performance of modified asphalt. Fourier transform infrared spectroscopy was carried out to analyze the modification mechanism of modified asphalt. Finally, the rutting, low‐temperature bending beam failure, and freeze–thaw splitting tests were used to evaluate the high‐temperature performance, low‐temperature cracking resistance, and water stability performance of mixtures, respectively. The results show that the high‐temperature performance of asphalt can be improved by BRA with asphaltene and resin increased. It is likely that there is no new functional group generated and this process was physical changes mainly. The honeycomb structure of BRA ashes/particles increased the contact area between the base asphalt and BRA ashes/particles, which makes the asphalt change from the homogeneous body into a two‐phase continuous structure system. Consequently, the adhesion between asphalt and BRA ashes/particles was enhanced, and the dynamic stability, bending coefficient and splitting strength ratio were improved. It indicates that the test results of asphalt mixtures verified the modification effect of BRA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46903. The diagram of modification mechanism of BRA in asphalt. (a) compatibility between BRA ash and base asphalt. (b) compatibility between powders and base asphalt. [ABSTRACT FROM AUTHOR]