The performance of reinforced concrete bridge deck pavement will be gradually reduced with the increase of operation time, so the reasonable maintenance measures should be taken to ensure the performance and safety of the bridge structures. The objectives and their hierarchical structures from both state position and enterprise position of the decision makers in bridge engineering decision-making problems were discussed. By the existing deterioration model, this paper studies the bridge operation safety maintenance strategy, establishes the mathematical model of the influence of different degrees of maintenance measures on the structural performance, combines with the cost-benefit theory, establishes the maintenance risk decision criteria for the decision makers with different objectives, and makes the decision on the selection of the bridge deck pavement scheme based on the enterprise position through an example.
To explore the effect of nano-attapulgite clay (NAC) on the durability of concrete, two kinds of NAC (calcined raw ore and calcined high viscosity ore: calcination at 650 °C for 2 h) were used to study their effects on the durability of concrete, mainly discussing the changes of chloride ion permeability and the resistivity of concrete with NAC. The effect of NAC on the strength of concrete was analyzed by testing the compressive strength of concrete. The two-electrode method, four-electrode method, and concrete resistivity tester were used to analyze the relationship between the testing method and concrete resistivity, and the effect of NAC on concrete resistivity was analyzed. The influence of NAC on the chloride corrosion resistance of concrete was analyzed by measuring the chloride diffusion coefficient, and the relationship between the chloride diffusion coefficient and resistivity was established. The diffusion process of chloride ions in concrete was analyzed by theoretical derivation and numerical simulation. The results show that: calcining raw ore NAC can improve the compressive strength of concrete, while calcining high-viscosity ore reduces the compressive strength of concrete. At the age of 28 days, the strength of concrete mixed with calcined raw ore is about 7.10% higher than that of ordinary concrete, while the compressive strength of concrete mixed with calcined high-viscosity ore is about 4.32% lower than that of common concrete. The resistivity of concrete mixed with calcined raw ore increases the fastest, and the 56 days age is about 15.8% and 29.6% higher than that of ordinary concrete and calcined high-viscosity ore. There is a good negative correlation between concrete resistivity and chloride diffusion coefficient. At 28 days, the incorporation of calcined raw ore concrete decreased by about 19.9% and 49.4% compared with ordinary concrete and calcined high-viscosity ore, respectively. After 10 years of decline, the chloride ion content is 11.1% and 23.2% lower than that of ordinary concrete and concrete mixed with calcined high viscosity ore.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.