In this study, a shape memory alloy (SMA) and general rubber bearing are used to develop a novel SMA–rubber bearing combination. This bearing is then used to develop a smart isolation system that can achieve vibration control in a bridge structure during earthquakes. The system design is based on a martensitic NiTi SMA (atom fraction of $\mathrm{Ni}=51\%$ ) with a production diameter of 1.0 mm. The damping provided by the NiTi alloy is frequency dependent and increases with prestrain and amplitude. To investigate the basic mechanical behavior of the designed SMA-rubber bearing, three-dimensional finite-element models were constructed and the optimized parameters of the bearing were analyzed to investigate their effects on mechanical behavior. To assess the isolation effectiveness of the bearing, a simply supported beam bridge with different bearings was investigated under various earthquake excitations to compare the effects of vibration isolation. Through optimization analysis, design parameters for prestrain (3.0–4.0%), $\alpha$ value (18–25°), and Shore hardness were obtained. An application analysis showed that the proposed bearings limit the relative displacement of a bridge deck effectively under strong ground motions and that they almost completely recover their original shape.

Studies on the fatigue behaviour of composite deck slabs are relatively few. To assess the fatigue performance of a composite deck slab at specific design loads, and to provide a reference for its design in fatigue, two full-scale models A and B of a composite deck slab were developed, comprising steel plates and steel-fibre-reinforced concrete slabs. These models will be a useful reference for experiments and design, and for developing codes. In this study we carried out fatigue experiments and focused on the fatigue performance of a composite deck slab in a column area, and the positive and negative bending moments. For the entire fatigue loading cycle, the overall performance of Models A and B was good, the overall stiffness of the composite deck slab was rarely attenuated, the stress levels in the steel members in relation to the fracture strength were not significant, and the steel member was in the stage of flexible work. Through comprehensive tests of Models A and B it was found that the original design exhibits good fatigue performance and meets the design requirements. The research results provide a basis for the design of a composite bridge deck slab in fatigue.

The persistence of pothole maintenance represents an enduring challenge. Past studies have largely concentrated on the materials and techniques used for remediation, with a lack of attention given to the pothole interface. This paper employed epoxy asphalt rubber (EAR-10) as the repair material, exploring the impact of coupled temperature-dynamic loading on the mechanical response of the interface. Finite element modelling (FEM), adopting the viscoelastic characteristics of EAR-10, was deployed to investigate the mechanical response of the interface under three temperature service conditions high, medium, and low when a dynamic load traversed the pothole. The stress variations in the interface at various inclinations and thicknesses of the repair blocks were also studied. In addition, the comparative analysis of high-temperature rut resistance for powdered rubber composite-modified asphalt and SBS modified asphalt was conducted via the multiple stress examination in terms of its high-temperature resilience, resistance to moisture-induced damage, and fatigue life by employing the asphalt mixture rutting test, low-temperature bending test on small beams, and the water immersion Marshall stability test, respectively. The repair efficacy of EAR-10 was appraised through post-repair water immersion rutting tests and bending tests on composite structural small beams. The results indicated that incorporating coupled temperature-dynamic loading led to a considerable increase in stress, particularly under low-temperature service conditions. An inclination angle of 30 degrees was found to be optimal for the interface. The research methodology presented here is pertinent to guiding the pothole repair in the steel bridge pavement, ensuring the strength and durability of the interface rivals that of newly constructed layers.

According to asphalt-mortar theory, asphalt mixture is a dispersed system with the structure of multi-level space composite materials consisting of coarse aggregate, fine aggregate, mineral filler, and asphalt. It is a rough dispersed system that considers coarse aggregate as the dispersed phase dispersed in a dispersion medium of asphalt mortar. The asphalt mortar is a micro-dispersed system that considers mineral filler as the dispersed phase dispersed in a dispersion medium of high-consistency asphalt. It is well known that asphalt mortar is composed of mineral filler, fine aggregate, and asphalt, which act as a bonding aggregate and fill air voids' role in the asphalt mixture. Therefore, asphalt mortar has great effects on the properties of asphalt mixture. The hig- temperature properties and dynamic rheological properties of asphalt, asphalt mortar, and asphalt mixture are analyzed and compared. The rheological characteristics of asphalt mortar are tested using repeated creep recovery method. The accumulated strain and rheological index Gv are used to evaluate the high-temperature properties of asphalt mortar and asphalt mixture. The relation between asphalt mortar and asphalt mixture are analyzed according to the two indexes.

Owing to certain inherent deficiencies in their properties, fine reclaimed asphalt pavement (RAP) particles have not yet been widely reused worldwide, resulting in significant environmental pollution and economic waste. Currently, a diverse array of design methods for asphalt mixes has been proposed. These methods can exert a varying influence on the degree of blending (DoB) and the performance of recycled hot-mix asphalt containing fine RAP particles, and some methods may be better suited for recycling fine RAP particles. However, the specific effects and differences among these various methods have yet to be fully revealed. Therefore, this research comprehensively explored these behaviors. Four distinct mix design formulations were investigated: the dense-graded Asphalt Concrete Group (Group AC), the Stone Mastic Asphalt Group (Group SMA), the High-modulus Asphalt Concrete Group (Group HMAC), and the rejuvenator-modified Asphalt Concrete Group (Group AC+Re). It can be found that the DoB and performance varied across different groups. The DoB spanned from 69% to 82%, with Group SMA showing the highest and Group HMAC exhibiting the lowest. The tensile strength ratio (TSR) of Group AC performed only 73.7%, failing to meet the specification threshold; nevertheless, this shortfall can be compensated by employing alternative methods or adding rejuvenator. Group HMAC exhibited the highest splitting-tensile strength and fracture energy. In addition, the incorporation of rejuvenator can enhance most performance of mixes. Some findings may provide a new perspective for the application of fine RAP particles.