Probability prediction method for chloride ion concentration of concrete surface of marine tidal zone

Abstract

The invention discloses a probability prediction method for chloride ion concentration of a concrete surface of a marine tidal zone. The method comprises the following steps of (1) building a random sample point calculation model of the chloride ion concentration of the concrete surface of the marine tidal zone; (2) determining statistical eigenvalues of probability model parameters of different concretes of the marine tidal zone, and generating random sample points of the probability model parameters; and (3) generating random sample points of the chloride ion concentration of the concrete surface of the marine tidal zone, and determining a probability density function of the chloride ion concentration of the concrete surface of the marine tidal zone. According to the method, the influence of a water-binder ratio, concrete types and exposure time can be comprehensively considered, and a probability distribution characteristic of the chloride ion concentration of the concrete surface of the marine tidal zone can be reasonably described, so that the technical defect of a conventional deterministic prediction model is overcome.

Description

technical field [0001] The invention relates to a method for predicting the concentration of chloride ions on the surface of concrete, in particular to a method for probabilistically predicting the concentration of chloride ions on the surface of concrete in an ocean tidal zone. Background technique [0002] In the chloride environment in the ocean tidal zone, the corrosion of steel bars and cracking of concrete caused by the intrusion of chloride ions into the concrete are important reasons for the deterioration of the durability of concrete structures. Since the concentration of chloride ions on the surface of concrete is an important quantitative index reflecting the intensity of corrosion of concrete structures by the chloride environment in the ocean tidal zone, it is also an important quantitative boundary condition for the quantitative analysis and design of the durability of concrete structures in the chloride environment of the ocean tidal zone, so the establishment ...

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Problems solved by technology

[0005] The above papers are mainly based on field test data to analyze the influence of dry-wet time ratio and compressive stress on the chloride ion concentration on the concrete surface and the time-varying characteristics of the chloride ion concentration on the concrete surface, but no prediction model for the chloride ion concentration on the concrete surface in the ocean tidal zone has been established.

[0006] JTS 153-2015 "Durability Design Standards for Water Transport Engineering Structures" issued by the Ministry of Transport of the People's Republic of China in 2015 uses the water-cement ratio as the control parameter to establish a prediction model for the concentration of chloride ions on the concrete surface in the ocean water level fluctuation area, but does not consider Effect of mineral admixture type and exposure time

[0007] In 2010, Wang Xiaozhou and Jin Weiliang published a paper titled "Research on the Chloride Ion Erosion Law in the Dry-wet Alternating Area of ​​Concrete Structure of Seaport Wharf", based on the on-site detection data of the ocean tidal zone of Zhapu Port Wharf in Zhejiang, comprehensively considering the ambient temperature and relative humidity , seawater infiltration time and water-binder ratio, and established a prediction model for the concentration of chloride ions on the concrete surface in the ocean tidal zone, but this model did not consider the impact of the type of mineral admixture and exposure time on the concentration of chloride ions on the concrete surface, and was based on Established on-site detection data of specific geographical and environmental conditions at Zhapu Port, Zhejiang, lack of universality

The model considers comprehensive factors, but it belongs to the deterministic prediction model, which can only guarantee the overall optimum of the prediction results and test values, but cannot describe the probability distribution characteristics of the chloride ion concentration on the concrete surface

[0009] In 2013, Zhong Xiaoping, Jin Weiliang, and Wang Yi published a paper titled "Criteria for Values ​​of Variable Effects of Concrete Structures in Port Engineering", combined with literature research and engineering experience, determined the concentration of chloride ions on the concrete surface in the ocean tidal splash zone However, the influence of the water-binder ratio, the type of mineral admixture and the exposure time on the probability distribution characteristics of the chloride ion concentration on the concrete surface in the ocean tidal zone cannot be considered

[0010] So far, there is no report on a probabilistic prediction method that can not only comprehensively consider the influence of water-cement ratio, concrete type and exposure time, but also reasonably describe the probability distribution characteristics of the chloride ion concentration on the concrete surface in the ocean tidal zone.

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