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This study examines the design and utilization of shared streets in the Jiefangbei Business District of Chongqing through the lens of geographical semiotics. Employing photo content analysis, video observation, and questionnaire surveys, this research delves into visual semiotics, place semiotics, and users' interaction order, including social interactions and traffic experiences within these shared spaces. The findings reveal that two distinct systems guide pedestrians and vehicles on Jiefangbei's shared streets, ensuring safety and cultural expression. Paving is identified as the most important method for realizing the sharing of space between people and vehicles. Street furniture emphasizes multifunctional composite use and reflects Jiefangbei's eclectic style since its era as a financial center of the Republic of China, responding to cultural resources and functional positioning. The study also indicates that social functions and public space attributes need enhancement, recommending more greenery and leisure facilities. Interaction order analysis shows that participants' perception of street sharing does not affect their sense of safety and effectiveness. Thus, future practice should base decisions on specific traffic conditions and urban functions. A limitation of this study is the inability to accurately sample the population structure of the Jiefangbei commercial district, preventing more adaptable conclusions. The authors suggest viewing shared space as an evolving process and recommend future research on long-term effects and cross-cultural comparative studies to provide valuable insights into global shared-street design. [ABSTRACT FROM AUTHOR]

To improve the performance of shotcrete in high-altitude and low-temperature environments, emulsified asphalt shotcrete (EASC), which can be used in negative-temperature environments, was prepared by using low-freezing-point emulsified asphalt, calcium aluminate cement, and sodium pyrophosphate as modified materials. The effect of emulsified asphalt on the performance of shotcrete was investigated through concrete spraying and indoor tests. Then, the modification mechanism of emulsified asphalt with respect to EASC was analyzed by combining scanning electron microscopy images and the pore structure characteristics of EASC. The results showed that in a negative-temperature environment, the incorporation of emulsified asphalt delayed the formation of the peak of the cement hydration exotherm, slowed the rate of the cement hydration exotherm, reduced the thermal perturbation of permafrost by EASC, increased the cohesion of the concrete, improved the bond strength between EASC and permafrost, and reduced the rate of rebound. The mechanical strength of the studied EASC decreased upon increasing the amount of emulsified asphalt in the admixture, and its resistance to cracking gradually improved. A content of less than 5% emulsified asphalt could improve the internal pore structure of EASC, thus improving its durability. Increasing the content of emulsified asphalt affected the hydration process of the cement, and the volume content of the capillary pores and macropores increased, which reduced the durability of the EASC. [ABSTRACT FROM AUTHOR]

To develop a cement emulsified asphalt composite (CEAC) that can be sprayed under a plateau negative temperature environment, the effects of the water-solid ratio, calcium aluminate cement substitution rate, emulsified asphalt content, sand-binder ratio, and polyvinyl alcohol (PVA) fiber content on the spraying performance and rheological parameters of CEAC were explored through the controlled variable method. Additionally, the correlation between the spraying performance and rheological parameters of CEAC was established, and the optimal proportion of CEAC was determined. Then, the difference in frost resistance and pore structure between the cement slurry (CS) without emulsified asphalt and CEAC at the optimum proportion was analyzed. The results showed that the optimum proportions for sprayed CEAC were 0.14 water-solid ratio, 0.5 sand-binder ratio, 25% substitution of calcium aluminate cement, 5% emulsified asphalt content, and 1.5% PVA fiber volume mixing. The yield stress and plastic viscosity of CEAC were positively correlated with the build-up thickness, whereas the rebound rate and the latter showed a negative correlation. The spraying performance may be described by the rheological parameters; the ranges of yield stress and plastic viscosity of 2.37-3.95 Pa·s and 77.42-108.58 Pa, respectively, produced the best spray ability. After undergoing an equivalent number of freeze-thaw cycles, CEAC exhibited lower mass and strength loss rates compared to CS, thereby demonstrating superior frost resistance. In addition, the pore structure analysis showed that the difference in capillary and macropore contents was the main reason for the variability in frost resistance between CS and CEAC.