Concrete with light weight and pervious performance has been widely recognized as an effective and sustainable solution for reducing the negative impacts of urbanization on the environment, as it plays a positive role in urban road drainage, alleviating the urban heat island effect and thermal insulation, as well as seismic performance, etc. This research paper presents a feasibility study of pervious concrete preparation with ceramsite as aggregate. First, pervious concrete specimens with different types of aggregates at various water–cement ratios were prepared, and the mechanical properties of pervious concrete specimens were evaluated based on the compressive strength test. Then, the permeability properties of the pervious concrete specimens with different types of aggregates at various water–cement ratios were characterized. Meanwhile, statistical analysis and regression fitting were conducted. Finally, the analysis of the freeze–thaw durability of pervious concrete specimens with ceramsite as aggregate according to indexes including quality loss rate and strength loss rate was performed. The results show that as the water–cement ratio increased, the compressive strength and permeability coefficient of pervious concrete generally decreased. Compressive strength and permeability coefficient showed a great correlation with the water–cement ratio; the R² values of the models were around 0.94 and 0.9, showing good regression. Compressive strength was mainly provided by the strength of the aggregates, with high-strength clay ceramsite having the highest 28-day compressive strength value, followed by ordinary crushed-stone aggregates and lightweight ceramsite. Porosity was mainly influenced by the particle size and shape of the aggregates. Lightweight ceramsite had the highest permeability coefficient among different types of cement-bound aggregates, followed by high-strength clay ceramsite and ordinary crushed-stone aggregates. The quality and compressive strength of pervious concrete specimens decreased with the increase in freeze–thaw cycles; the quality loss was 1.52%, and the compressive strength loss rate was 6.84% after 25 freeze–thaw cycles. Quadratic polynomial regression analysis was used to quantify the relationship of durability and freeze–thaw cycles, with R² of around 0.98. The results provide valuable insights into the potential applications and benefits of using ceramsite as an aggregate material in pervious concrete for more sustainable and durable infrastructure projects.

As an important part of the transportation network, the reliability of bridge structures is of great significance to people’s personal safety, as well as to the national economy. In order to evaluate the performance of complex bridge structures, their mechanical behavior and fundamental characteristics need to be studied. Structural health monitoring (SHM) has been introduced into bridge engineering, and the structural response assessment, load effects monitoring, and reliability evaluation have been developed based on the collected SHM information. In this study, a performance evaluation method for complex bridge structures based on non-destructive field loading tests is proposed. The cable-stayed bridge in Guangxi with the largest span (Pingnan Xiangsizhou Bridge) was selected as the research object, and loading on the main girder was transferred to the piers and tower through the stay cables, whose structural responses are critical in the process of bridge operation. Therefore, the field loading tests—including deflection and strain testing of the main girder, as well as cable force tests—were also conducted for Pingnan Xiangsizhou Bridge by using non-destructive measurement techniques (multifunctional static strain test system, radar interferometric deformation measurement technology, etc.). Based on the numerically simulated results of a finite element model for Pingnan Xiangsizhou Bridge, reasonable field loading test conditions and loading arrangement were determined. Non-destructive field loading test results showed that the quality of the bridge’s construction is up to standard, due to a good agreement between the calculated and measured frequencies of the bridge. In addition, the calibration coefficients of displacement and strain were less than 1, indicating that Pingnan Xiangsizhou Bridge has satisfactory stiffness and strength.

The hanger often needs to be replaced many times during the operation period of hanger arch bridges. To ensure the safety of the hanger replacement in the construction process of pocket hanging, the structural response in the whole construction process needs to be precisely controlled. In this paper, aiming at half-through arches with a suspended deck by cable hangers, the precise displacement controlling method for hanger replacement of an arch bridge based on the pocket hanging method has been proposed. Firstly, the equivalent model of an arch bridge in the hanger replacement process is established, and the boundary conditions of the equivalent model are calculated precisely. Secondly, in the hanger replacement process, including old hanger demolition and new hanger installation, the precise displacement expressions of the suspended deck are derived on the basis of the equivalent model. Finally, the correctness and feasibility of the proposed precise displacement controlling method are verified by the hanger replacement engineering of an arch bridge. Through this research on the hanger replacement of an arch bridge, the equivalent model adopted in this paper has been proven accurate, and only partial boundary conditions need to be considered in practical engineering applications to get accurate results. Meanwhile, the calculation results are accurate enough through the practical engineering verification, and the precise displacement controlling method is feasible in the hanger replacement process of an arch bridge based on the pocket hanging method. It is also found that satisfactory results can be achieved using hanger demolition and installation by equal step length.

Because of their beautiful appearance, strong crossing ability, and reasonable stress performance, the application of tied steel box arch bridges is becoming more and more extensive. Bridge construction monitoring can control and adjust the deviation state to ensure the stress and linear state of the bridge after completion. This study carried out a symmetrical construction monitoring analysis and completed state evaluation of the newly built Dafeng River Bridge in Guangxi Province based on the finite element method. MIDAS Civil finite element software is used for simulation analysis to calculate the deformation and stress of the tied steel box arch bridge at the construction and completion stages. The tensile and compressive stress of the main arch and transverse brace, as well as the cumulative displacements of the main arch and lattice beam, are symmetrically distributed. The maximum tensile and compressive stresses are 15.1 MPa and 74.6 MPa, respectively, less than the specification’s allowable value. Meanwhile, for the completed bridge under the loading combinations of serviceability limit state and bearing capacity ultimate limit state, the stress of the main arch, transverse brace, and lattice beam meets the specification requirements. The maximum cable forces of the suspender and tie rod under the bearing capacity ultimate limit state are 2189.4 kN and 2991.2 kN, and their corresponding minimum safety factors are 3.2 and 2.7. In addition, the deviations between the on-site monitoring and the finite element theoretical values are within the specification allowable range for the cable force of the suspender and tie rod and the bridge deck alignment. It indicates that the bridge construction monitoring effect is reasonable and ideal, and the symmetrically finite element simulation analysis can provide a theoretical basis for construction monitoring.

The utilization of recycled aggregate can avert the squandering of resources and the destruction of the environment. Nevertheless, there exists a slew of old cement mortar and microcracks on the surface of recycled aggregate, which give rise to the poor performance of aggregates in concrete. In this study, for the sake of ameliorating this property of recycled aggregates, the surface of the recycled aggregates is covered with a layer of cement mortar to compensate for the microcracks on the surface and reinforce the bond between old cement mortar and aggregates. In order to demonstrate the influence of recycled aggregate by different cement mortar pretreatment methods, this study prepared natural aggregate concrete (NAC) and concretes with recycled aggregate after the wetting pretreatment (RAC-W) and cement mortar pretreatment (RAC-C), and conducted uniaxial compressive strength tests on different types of concrete at different curing ages. The test results indicated that the compressive strength of RAC-C at a 7 d curing age was higher than that of RAC-W and NAC, and the compressive strength of RAC-C at a 28 d curing age was higher than RAC-W but lower than NAC. The compressive strength of NAC and RAC-W at a 7 d curing age was about 70% of that at a 28 d curing age, and the compressive strength of RAC-C at a 7 d curing age was about 85–90% of that at a 28 d curing age. The compressive strength of RAC-C increased dramatically at the early stage, while the post-strength of the NAC and RAC-W groups increased rapidly. The fracture surface of RAC-W mainly occurred in the transition zone between the recycled aggregates and old cement mortar under the pressure of the uniaxial compressive load. However, the main failure of RAC-C was the crushing destruction of cement mortar. With changes in the amount of cement added beforehand, the proportion of aggregate damage and A-P interface damage of RAC-C also changed accordingly. Therefore, the recycled aggregate pretreated with cement mortar can significantly improve the compressive strength of recycled aggregate concrete. The optimal amount of pre-added cement was 25%, which is recommended for practical engineering.

A suspended dense graded broken stone road foundation stabilized by cement is a commonly employed material in roadworks, which is vulnerable to harm caused by freezing and thawing processes. This investigation intends to evaluate the laboratory behavior and the characteristics of freezing and thawing process-induced deterioration in a broken stone road foundation stabilized by cement with suspended dense grading, employing mechanical examinations and acoustical methods. The rate of mass loss in the broken stone road foundation stabilized by cement progressively rises, and the rate of decline in the compressive strength could potentially intensify as freezing and thawing processes augment. The modulus of resilience diminishes as freezing and thawing processes progress, and ultrasonic wave velocity also decreases. The patterns of mass loss, compressive strength decline, resilience modulus reduction, and ultrasonic wave velocity alteration adhere to a parabolic fitting relationship with freeze–thaw cycles, with an R² above 0.95. The curves depicting the relationship of mass, compressive strength, resilience modulus, and ultrasonic wave velocity exhibit a steeper trend significantly after 10–15 cycles, which can be ascribed to the emergence of microcracks and the progression of flaws within the material. The evolution of damage in the broken stone road foundation stabilized by cement is monitored to progress through three distinct stages based on acoustic emission: initial, stationary, and failure. As freezing and thawing processes accumulate to 20 cycles, the length of initial phase correspondingly rises to three times, the length of failure stage diminishes to about one fifth.