In engineering practice, similar surface insulation measures are typically applied to different parts of mass concrete surfaces. However, this can lead to cracking at the edges of the concrete surface or the wastage of insulation materials. In comparison to flat surfaces, the edges of mass concrete structures dissipate heat more rapidly, leading to more pronounced stress concentration phenomena. Therefore, reinforced insulation measures are necessary. To reduce energy consumption and enhance overall insulation effectiveness, it is essential to study the specific insulation requirements of both the flat surfaces and edges of concrete separately and implement targeted surface insulation measures. Taking the bridge abutment planned for pouring in Nanjing City as the research object, this study established a finite element model to explore the effects of different ambient temperatures and different surface heat dissipation coefficients on the early-age temperature and stress fields of different parts of the abutment’s surface. Based on simulation results, reasonable heat dissipation coefficients that meet the requirements for crack prevention on both the structure’s plane and edges under different ambient temperatures were obtained. The results indicate that under the same conditions, the reasonable heat dissipation coefficient at the edges was smaller than that on the flat surfaces, indicating the need for stronger insulation measures at the edges. Finally, mathematical models correlating ambient temperature with reasonable heat dissipation coefficients for the structure’s plane and edges at these temperatures were established, with high data correlation and determination coefficients (R²) of 0.95 and 0.92. The mathematical models were validated, and the results from finite element calculations were found to be consistent with those from the mathematical models, validating the accuracy of the mathematical models. The conclusions drawn can provide references for the insulation of similar engineering concrete planes and edges.

This study examined a newly developed environmentally friendly plant-based corrosion inhibitor (Xanthium sibiricum). The natural potential method, linear polarization method, steel weight loss method, and corrosion area method were employed to verify the inhibitor’s effectiveness in chloride-containing concrete. The results indicated that Xanthium sibiricum elevated the natural potential of reinforcing steel in concrete, increased its self-corrosion potential, and reduced the self-corrosion current. After three months of curing, the corrosion rate of steel without an inhibitor was approximately 47.5% faster than the experimental group, with the steel loss rate about 40% more severe. The effectiveness of the inhibitor was influenced by increased chloride content in concrete. A two-dimensional multiphase ion transport model of reinforced concrete with realistic aggregate distribution was established using the finite element method (FEM). This model simulated chloride ion transport under typical civil engineering service environments—the coupled effects of a stray current and chloride environment. A predictive formula for the residual compressive strength of reinforced concrete was derived after corrosion under various voltages and chloride ion concentrations for a specific duration. In conjunction with a pump station project operating in a similar environment, the optimal dosage of the Xanthium sibiricum inhibitor for practical engineering was determined to be 2 g/L. At this dosage, the strength of reinforced concrete specimens increased by approximately 31.1%. Finally, a predictive formula for the residual compressive strength of reinforced concrete with an added inhibitor was obtained after corrosion under various voltages and chloride ion concentrations for a specific duration. The conclusions can enhance the durability and safety of concrete structures in similar projects, showing promising application prospects.

This study builds on the practice of using waste rubber to improve the ductility of cement mortar and further explores the potential of vinyl acetate-ethylene (VAE) in enhancing the ductility of rubber cement mortar (RM). It systematically analyzes the effects of VAE on the workability, mechanical properties, crack resistance, and microstructure of RM. Additionally, isothermal calorimetry was employed to investigate the mechanism of VAE’s influence on cement hydration heat. The results show that VAE significantly improves the flexural strength, tensile strength, and ultimate tensile strain of RM, while reducing its compressive strength and tensile elastic modulus, thereby markedly enhancing its flexibility and ductility. At a VAE content of 4%, the fluidity, 28-day flexural strength, tensile strength, and ultimate tensile strain of RM reached 240 mm, 4.83 MPa, 1.92 MPa, and 233 × 10⁻⁶, respectively, representing increases of 16%, 18.97%, 11.63%, and 62.94% compared to ordinary RM. However, when the VAE content exceeded 4%, both flexural strength and tensile strength began to decrease. Furthermore, the incorporation of VAE induced the formation of flexible polymer films within the RM matrix but also increased the porosity of the cement matrix, extended the induction period of cement hydration, and reduced the rate and degree of hydration. These findings provide valuable data to support the development of high-ductility and high-crack-resistance concrete repair materials.

Safety, progress, and investment risks are correlated during the construction period of large-scale water transfer projects. However, previous studies have only considered individual risk factors, overlooking the potential systemic risk posed to safety, progress, and investment, as well as any underlying common cause failures. Since traditional risk analysis methods are ill-suited to addressing common cause failure, this paper’s objective was to establish a comprehensive evaluation index framework and to identify the basic events of common cause failure. To do that, we developed a risk analysis method that models common cause failure based on a Bayesian network for assessing that systemic risk. The Henan Section of the Yangtze-to-Huaihe River Water Diversion Project in China was then used as a case study. The results show that a variety of common cause failure events, such as epidemic disease, design alteration, lagged approval process, heavy rain in the flood season, renewal material and failing equipment, construction accidents, and external interference, can significantly impact the safety, progress, and investment systemic risk. Design alteration poses the greatest risk, with renewal material and failing equipment exerting the strongest influence among all common cause failure events. It is also possible to elucidate the predominant causal chains; specifically, the contributing influence of each basic failure event to the systemic risk can be clarified by adjusting their respective initial state. The failure of renewal material and failing equipment was found to significantly increase the safety risk. This study effectively simulated the complex causal relationships and uncertainties of pertinent risk factors, thereby enhancing our understanding of the systemic risk associated with safety, progress, and investment in large-scale water transfer projects.