To address the vulnerability of rolling bearings to noise interference in industrial settings, along with the problems of weak noise resilience and inadequate generalization in conventional residual network frameworks, this study introduces an adaptive denoising residual network (AD-ResNet) for diagnosing rolling bearing faults. Initially, the sensors collect the bearing vibration signals, which are then converted into two-dimensional grayscale images through the application of a continuous wavelet transform. Then, a spatial adaptive denoising network (SADNet) architecture is incorporated to comprehensively extract multi-scale information from noisy images. By exploiting the improved pyramid squeeze attention (IPSA) module, which excels in extracting representative features from channel attention vectors, this unit substitutes the standard convolutional layers present in typical residual networks. Ultimately, this model was validated through experiments using publicly available bearing datasets from CWRU and HUST. The findings suggest that with −6 dB Gaussian white noise, the average accuracy of recognition achieves a rate of 90.96%. In scenarios of fluctuating speeds accompanied by strong noise, the recognition accuracy can reach 89.54%, while the training time per cycle averages merely 3.65 s. When compared to other widely utilized fault diagnosis techniques, the approach described in this paper exhibits enhanced noise resistance and better generalization capabilities.

The excessive extraction of river sand has led to significant ecological issues. Moreover, the environmental impact and resource demand of cement production have increasingly turned the spotlight on sea sand as a viable alternative due to its abundance and ease of extraction. Concurrently, alkali-activated binders, a novel type of low-carbon cementitious material, have gained attention for their low energy consumption, high durability, and effective chloride ion fixation capabilities. However, they are susceptible to carbonation. Introducing a controlled sea sand amount can raise the materials’ carbonation resistance, although carbonation may raise the concentration of free Cl⁻ within the structure to levels that could risk the integrity of steel reinforcements by accelerating corrosion. In this context, the current study investigates sea sand alkali-activated slag (SSAS) concrete prepared with varying water–binder (W/B) ratios to evaluate its impact on flowability, mechanical strength, performances, and chloride ion distribution post-carbonation. The results demonstrate that the mechanical property of SSAS concrete diminishes as the water-to-binder ratio increases, with a more pronounced reduction observed. The depth of carbonation in mortar specimens also rises with the W/B ratio, whereas the compressive strength post-carbonation initially decreases before showing an increase as carbonation progresses. Furthermore, carbonation redistributes chloride ions in SSAS, leading to a peak Cl⁻ concentration near the carbonation front. However, this peak amplitude does not show a clear correlation with changes in the W/B ratio. This study provides a theoretical foundation for employing sea sand and alkali-activated concrete.

This paper reports the numerical simulation of earthquake-damaged circular columns repaired with the combination of near-surface-mounted (NSM) basalt fiber reinforced polymer (BFRP) bars with external BFRP sheets jacketing at quasi-static loading. The numerical modeling was carried out with the nonlinear OpenSees software platform by using the BeamWithHinges element. In the simulations, the effect of the previous earthquake damage on the behavior of the repaired columns was taken into account, and a simple and effective material damage-accumulation model is proposed to modify the constitutive of materials in the unrepaired regions of the repaired columns. The developed numerical models were validated by comparing their quasi-static findings with those obtained from a previous experimental program, and a good agreement can be observed. Furthermore, the efficiency of the repair technique used in tests is evaluated via the developed numerical model.