The size, shape, gradation and appearance of aggregate have a significant impact on the road performance of asphalt mixtures, which is directly related to the deformation characteristics and fatigue resistance of asphalt mixtures. In order to be able to design a long-life asphalt pavement, the aggregate must have reasonable morphology and morphological characteristics. In order to quantitatively analyze the shape characteristics of the road coarse aggregate, a high-precision three-dimensional scanner is used to obtain the characteristic lattice of the aggregate surface, and the solid model of the coarse aggregate particles is established. The two-dimensional and three-dimensional morphological indicators of the aggregate are analyzed and discussed. Meanwhile, aggregates processed by typical quarries in Guangdong Province are collected, and the influence of different processing techniques on the morphology of aggregates are analyzed. The results show that the difference between the perimeter and projected area of the aggregate contour under different viewing angles is relatively large, which is closely related to the flatness index of the aggregate. It can better characterize the three-dimensional shape of the aggregate. The closer the aggregate is to the cubic state, the greater the sphericity value; the ellipsoid index calculated based on the three-dimensional circumscribed ellipsoid can better characterize the angularity of the aggregate. The worse the angularity of the aggregate, the larger the corresponding ellipsoid value. The sphericity of the aggregate processed by counter-breaking is lower, and the angularity is better. The sphericity of the aggregate processed by the shaping process is the best, but the angularity is lower. According to actual needs, different processing techniques can be combined and blended to obtain aggregate finished products with a more balanced grain shape and angularity. The richer the angularity of the coarse aggregate, the better the high-temperature stability and fatigue resistance of the asphalt mixture. However, the stability of performance indicators will become worse. In practical engineering applications, it is recommended to further combine the screening efficiency of the hot material screen of the mixing plant with the stability of the hot material gradation and the uniformity of construction quality to select a suitable aggregate processing technology.

Titanium dioxide (TiO₂) is widely employed in the catalytic degradation of wastewater, owing to its robust stability, superior photocatalytic efficiency, and cost-effectiveness. Nonetheless, isolating the fine particulate photocatalysts from the solution post-reaction poses a significant challenge in practical photocatalytic processes. Furthermore, these particles have a tendency to agglomerate into larger clusters, which diminishes their stability. To address this issue, the present study has developed Al₂O₃–SiO₂–TiO₂ composite semiconductor porous ceramics and has systematically explored the influence of Al₂O₃ and SiO₂ on the structure and properties of TiO₂ porous ceramics. The findings reveal that the incorporation of Al₂O₃ augments the open porosity of the ceramics and inhibits the aggregation of TiO₂, thereby increasing the catalytic site and improving the light absorption capacity. On the other hand, the addition of SiO₂ enhances the bending strength of the ceramics and inhibits the conversion of anatase to rutile, thereby further enhancing its photocatalytic activity. Consequently, at an optimal composition of 55 wt.% Al₂O₃, 40 wt.% TiO₂, and 5 wt.% SiO₂, the resulting porous ceramics exhibit a methylene blue removal rate of 91.50%, and even after undergoing five cycles of testing, their catalytic efficiency remains approximately 83.82%. These outcomes underscore the exceptional photocatalytic degradation efficiency, recyclability, and reusability of the Al₂O₃–SiO₂–TiO₂ porous ceramics, suggesting their substantial potential for application in the treatment of dye wastewater, especially for the removal of methylene blue.

Coarse aggregate is the main component of asphalt mixtures, and differences in its morphology directly impact road performance. The utilization of standard aggregates can benefit the standard design and performance improvement. In this study, 3D printing technology was adopted to prepare artificial aggregates with specific shapes for the purpose of making the properties of artificial aggregates to be similar to the properties of natural aggregates. Through a series of material experiments, the optimal cement-based material ratio for the preparation of high-strength artificial aggregates and corresponding manufacturing procedures have been determined. The performance of the artificial aggregates has been verified by comparing the physical and mechanical properties with those of natural aggregates. Results indicate that using 3D printing technology to generate the standard coarse aggregate is feasible, but its high cost in implementation cannot be ignored. The 3D shape of the artificial aggregate prepared by the grouting molding process has a good consistency with the natural aggregate, and the relative deviation of the overall macro-scale volume index of the artificial aggregate is within 4%. The average Los Angeles abrasion loss of artificial cement-based aggregate is 15.2%, which is higher than that of diabase aggregate, but significantly lower than that of granite aggregate and limestone aggregate. In a nutshell, 3D printed aggregates prepared using the optimized cement-based material ratio and corresponding manufacturing procedures have superior physical and mechanical performance, which provides technical support for the test standardization and engineering application of asphalt pavements.

Porous sound absorption ceramic is one of the most promising materials for effectively eliminating noise pollution. However, its high production cost and low mechanical strength limit its practical applications. In this work, low-cost and in situ mullite whisker-reinforced porous sound-absorbing ceramics were prepared using recyclable construction waste and Al₂O₃ powder as the main raw materials, and AlF₃ and CeO₂ as the additives, respectively. The effects of CeO₂ content, AlF₃ content, and sintering temperature on the microstructure and properties of the porous ceramics were systematically investigated. The results showed that a small amount of CeO₂ significantly promoted the growth of elongated mullite crystals in the resultant porous ceramics, decreased the growth temperature of the mullite whiskers, and significantly increased the biaxial flexural strength. When 2 wt.% CeO₂ and 12 wt.% AlF₃ were added to the system, mullite whiskers were successfully obtained at a sintering temperature of 1300 °C for 1 h, which exhibited excellent properties, including an open porosity of 56.4 ± 0.6%, an average pore size of 1.32–2.54 μm, a biaxial flexural strength of 23.7 ± 0.9 MPa, and a sound absorption coefficient of >0.8 at 800–4000 Hz.