WO2024239355A1 - 一种高原环境考虑防护与修复效果的混凝土寿命计算方法 - Google Patents

一种高原环境考虑防护与修复效果的混凝土寿命计算方法 Download PDF

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WO2024239355A1
WO2024239355A1 PCT/CN2023/097012 CN2023097012W WO2024239355A1 WO 2024239355 A1 WO2024239355 A1 WO 2024239355A1 CN 2023097012 W CN2023097012 W CN 2023097012W WO 2024239355 A1 WO2024239355 A1 WO 2024239355A1
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concrete
repair
plateau environment
plateau
protection
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French (fr)
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王凤娟
王赟程
蒋金洋
穆松
刘志勇
李映泽
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Southeast University
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    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
    • G01N33/383—Concrete or cement
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2111/00—Details relating to CAD techniques
    • G06F2111/10—Numerical modelling
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/04—Ageing analysis or optimisation against ageing
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/08—Thermal analysis or thermal optimisation
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

Definitions

  • the invention belongs to the field of concrete service life calculation, and in particular relates to a concrete service life calculation method taking into account protection and repair effects in a plateau environment.
  • the purpose of the present invention is to provide a method for calculating the service life of concrete taking into account the protection and repair effects in a plateau environment, so as to solve the problem that the existing method cannot calculate the service life of concrete taking into account the protection and repair effects in a plateau environment.
  • the present invention provides a method for calculating the life of concrete in a plateau environment taking into account protection and repair effects, comprising the following steps:
  • the mapping relationship between the plateau environment, load parameters and time is fixed or arbitrarily changing temperature, humidity, salt concentration and internal and external force loads;
  • salt is the corrosive medium, including: sodium chloride, calcium chloride, cesium chloride, sodium sulfate, magnesium sulfate;
  • internal and external force loads include: gravity, internal pore expansion force, external load.
  • the construction process of the concrete geometric model is: using the Monte Carlo method to randomly generate the concrete microstructure, adding a protective coating geometric model of arbitrary thickness to the surface of the concrete, the protective coating geometric model is a line segment connected to the concrete in the 1D structure, a tetrahedron fitted to the concrete in the 2D model, and a hexahedron fitted to the concrete in the 3D structure model, and the damage repair material is a lattice or space domain uniformly distributed inside the cement paste;
  • the concrete geometric model includes coarse aggregate, fine aggregate and cement paste
  • the coarse and fine aggregate grading type can be freely set
  • the aggregate volume fraction is between 0% and 80%
  • the concrete surface protective coating is a continuous coating adhered to the concrete surface
  • the concrete repair material is uniformly distributed in the cement paste in the form of a field, which automatically triggers the repair effect after damage occurs, reduces the transmission rate of the erosion medium and restores the mechanical properties of the concrete.
  • the material phase includes: aggregate, slurry, and coating
  • the material properties of the slurry include: elastic modulus, Poisson's ratio, density, tensile strength, fracture energy, phase change temperature, phase change temperature interval, phase change latent heat, thermal conductivity, constant pressure heat capacity, ion diffusion coefficient, porosity, pore size distribution;
  • the material properties of the coating include: thermal conductivity, constant pressure heat capacity, and ion diffusion coefficient;
  • the relevant experimental parameters of the aggregate and the coating are obtained through experimental tests; the slurry is composed of sand and cement slurry, and the parameters of the slurry are calculated by the micromechanical equivalent medium theory.
  • the multi-factor coupling physical field equations include: temperature conduction equation, moisture transport equation, salt transport equation and force action equation;
  • the temperature conduction equation is:
  • ⁇ density
  • C specific heat capacity
  • T temperature
  • t time
  • ⁇ thermal conductivity
  • L latent heat of phase change
  • ⁇ L water content
  • the internal initial temperature is set to be consistent with the initial temperature of the plateau environment
  • the boundary condition uses the Dirichlet boundary condition, which is consistent with the plateau environment temperature parameter determined in S1;
  • Pc is the moisture characteristic curve
  • Ksl is the permeability coefficient of water in the material under saturated state
  • ⁇ is the viscosity of water
  • K rl is the relative permeability coefficient of the liquid phase
  • M w is the molar mass of water
  • R is the relative gas constant
  • ⁇ l is the density of water
  • D g0 is the free diffusion coefficient of water vapor in the air
  • P gs is the saturated vapor pressure
  • the internal initial moisture content is set according to the actual concrete, ranging from 0 to 100 RH%, and the boundary condition uses the Dirichlet boundary condition, which is consistent with the plateau environmental moisture parameters determined in S1;
  • salt transport equation is as follows:
  • c is the salt ion concentration
  • D 0 is the reference ion diffusion coefficient in the slurry
  • t 0 is the time for measuring the reference ion diffusion coefficient
  • m is the time dependence coefficient
  • ⁇ c is the critical pore saturation
  • U is the ion activation energy in the concrete
  • T ref is the temperature when the reference ion diffusion coefficient is measured
  • d is the damage factor obtained by the damage mechanics energy method
  • f r is the repair rate of the repair material to the damage
  • D f is the diffusion coefficient of the ion in water
  • R b is the influence factor of the concrete on the binding of the ion
  • the internal initial ion concentration is set to 0, and the boundary condition uses the Dirichlet boundary condition, which is consistent with the plateau environment ion parameters determined in S1;
  • ⁇ stress
  • b Biot coefficient
  • p * equivalent load of environmental action, which includes equivalent load of internal expansion caused by freeze-thaw and sulfate factors
  • p FT * is the internal expansion load caused by freeze-thaw
  • r max and r min are the maximum and minimum pore sizes in the matrix
  • K, K L and K C are the matrix moduli of slurry, water and ice, respectively
  • ⁇ is the strain of slurry
  • b L and b C are the Biot coefficients of water and ice, respectively
  • ⁇ s is the thermal expansion coefficient of slurry
  • p atm is the plateau ambient air pressure
  • p atm0 is the ambient air pressure when pouring slurry
  • S C , S L and S G are the volume fractions of ice, water and pores at the corresponding temperature
  • p s * is the equivalent internal expansion load caused by sulfate erosion
  • v AFt is the volume fraction of expanded ettringite
  • ⁇ i is the influencing factor of the corresponding environmental action
  • p i * represents the equivalent loads of freeze-thaw, sulfate and magnesium salt environments,
  • S5 is specifically as follows: the service life of the concrete is determined based on the life when the steel bar begins to corrode. The ion concentration at different depths is solved through steps S1-S4, and the service life of the concrete is determined by comparing the critical concentration. The steel bar corrosion repair material will increase the critical ion concentration of the steel bar. Therefore, the service life of the concrete is calculated as follows:
  • tc is the service life of concrete
  • xd is the buried depth of steel bars
  • frr is the action factor of steel bar corrosion repair materials
  • ccr is the inherent critical concentration of steel bar corrosion.
  • the present invention can simulate the internal temperature of concrete, humidity, stress response and service life, thus providing a basis for the design and construction of concrete structures in plateau environments.
  • FIG1 is a schematic diagram of a geometric model of a protective and repairing material in a two-dimensional form in an embodiment of the present invention
  • FIG2 is a schematic diagram of the distribution of the concentration of the corrosive medium at 0-5 mm on the concrete surface after using different types of protective coatings in an embodiment of the present invention
  • FIG3 is a schematic diagram of the distribution of the concentration of the corrosive medium at the buried depth of the steel bars after using different types of protective coatings in an embodiment of the present invention
  • FIG4 is a schematic diagram of the distribution of the concentration of the corrosive medium inside the concrete after using protective coatings of different thicknesses in an embodiment of the present invention
  • FIG5 is a schematic diagram of the distribution of the concentration of the corrosive medium inside the concrete after using the protective coatings with different lifespans in an embodiment of the present invention
  • FIG6 is a schematic diagram of the distribution of the concentration of the corrosive medium inside the concrete after using the crack repair material with a repair rate of 50% in an embodiment of the present invention
  • FIG7 is a schematic diagram of the distribution of the concentration of the corrosive medium inside the concrete after using the crack repair material with a repair rate of 70% in an embodiment of the present invention
  • FIG8 is a schematic diagram of the distribution of the concentration of the corrosive medium inside the concrete after using the crack repair material with a repair rate of 90% in an embodiment of the present invention
  • FIG9 is a schematic diagram showing a comparison between the concentration of the concrete corrosive medium and the critical concentration at the depth of the steel bar after the protective coating is applied in an embodiment of the present invention
  • FIG. 10 is a schematic diagram showing a comparison of the concentration of the concrete corrosive medium and the critical concentration at the depth of the steel bars after the damage repair material and the steel bars are repaired for corrosion in an embodiment of the present invention.
  • the purpose of the present invention is to provide a method for calculating the service life of concrete in a plateau environment taking into account the protection and repair effects, so as to solve the problem that the existing method cannot calculate the service life of concrete taking into account the protection and repair effects in a plateau environment.
  • step (3) Establishing the physical field equations of temperature-humidity-salt concentration-load multi-factor coupling, setting internal and external boundary conditions and initial conditions based on the concrete geometric model established in step (2), wherein the external boundary conditions are the mapping relationship between the plateau environment and load parameters and time determined in step (1);
  • the mapping relationship between the environment and load parameters and time in step (1) may be fixed or arbitrarily variable temperature, humidity and external load effects.
  • the concrete geometric model considering the protection and repair effects is randomly generated by the Monte Carlo method.
  • a protective coating geometric model of any thickness is added to the surface of the concrete.
  • the protective coating geometric model is a line segment connected to the concrete in the 1D structure, a tetrahedron fitted to the concrete in the 2D model, and a hexahedron fitted to the concrete in the 3D structure model.
  • the damage repair material is a lattice or space domain uniformly distributed inside the cement paste.
  • the concrete geometric model considering the protection and repair effects in step (2) contains physical phases such as aggregate, slurry, and coating.
  • the slurry needs to provide parameters including elastic modulus, Poisson's ratio, density, tensile strength, fracture energy, phase change temperature, phase change temperature interval, phase change latent heat, thermal conductivity, constant pressure heat capacity, ion diffusion coefficient, porosity, pore size distribution, etc.
  • the coating needs to provide thermal conductivity, constant pressure heat capacity, and ion diffusion coefficient.
  • the relevant experimental parameters of aggregate and coating are obtained through experimental tests. Since the slurry is composed of sand and cement slurry, it is a composite material, and the parameters of the slurry are calculated by the mesomechanical equivalent medium theory.
  • the multi-factor coupling physical field equations in concrete include the temperature conduction equation, the moisture transfer equation, the salt transfer equation and the force action equation.
  • the temperature conduction equation is as follows:
  • ⁇ density
  • C specific heat capacity
  • T temperature
  • t time
  • ⁇ thermal conductivity
  • L the latent heat of phase change
  • ⁇ L the moisture content
  • the internal initial temperature is set to be consistent with the initial temperature of the plateau environment, and the boundary condition uses the Dirichlet boundary condition, which is consistent with the plateau environment temperature parameters determined in step (1).
  • the water transport equation takes into account the two transport effects of gaseous water and liquid water, as shown below:
  • Pc is the moisture characteristic curve
  • Ksl is the permeability coefficient of water in the material under saturated state. is the porosity
  • ⁇ is the viscosity of water
  • K rl is the relative permeability of the liquid phase
  • M w is the molar mass of water
  • R is the relative gas constant
  • ⁇ l is the density of water
  • D g0 is the free diffusion coefficient of water vapor in the air
  • P gs is the saturated vapor pressure.
  • the internal initial moisture content is set according to the actual concrete, ranging from 0 to 100 RH%, and the boundary condition is the Dirichlet boundary condition, which is consistent with the plateau environmental moisture parameters determined in step (1).
  • c is the salt ion concentration
  • D0 is the reference ion diffusion coefficient in the slurry
  • t0 is the time for measuring the reference ion diffusion coefficient
  • m is the time dependence coefficient
  • ⁇ c is the critical pore saturation
  • U is the ion activation energy in concrete
  • Tref is the temperature when the reference ion diffusion coefficient is measured
  • d is the damage factor obtained by the damage mechanics energy method
  • fr is the repair rate of the repair material for the damage
  • Df is the diffusion coefficient of ions in water
  • Rb is the binding influence factor of concrete on ions.
  • the internal initial ion concentration is set to 0, and the boundary condition is the Dirichlet boundary condition, which is consistent with the plateau environment ion parameters determined in step (1).
  • ⁇ stress
  • b the Biot coefficient
  • p * is the equivalent load of environmental action.
  • the plateau environment it mainly includes the equivalent load of internal expansion caused by factors such as freeze-thaw and sulfate.
  • the equivalent load of internal expansion caused by freeze-thaw in plateau environment is solved according to the following steps: 1 first determine the content of gas, liquid and ice crystals in the pores of the slurry at a specific temperature; 2 calculate the internal expansion load based on the content of gas, liquid and ice crystals.
  • r c is the critical freezing pore size at the corresponding temperature
  • ⁇ CL is the water-ice interfacial energy
  • ⁇ m is the water-ice phase change entropy
  • ⁇ T is the temperature difference between the actual temperature in the plateau environment and the freezing point of the solution in the corresponding plateau pressure environment, which is affected by the plateau pressure, pores, etc.
  • ⁇ is the thickness of the water film on the pore wall, and the thickness is obtained by molecular dynamics simulation of the water distribution in the unsaturated CSH gel pores
  • S l0 (r), S C (r), S L (r) are the initial liquid water saturation function, ice crystal saturation function and liquid water saturation function under the corresponding pore size, respectively
  • S G is the gas saturation in the slurry pores
  • r sc is the critical saturated pore, which is also obtained by molecular dynamics simulation, is the porosity of pores smaller than r sc .
  • p FT * is the internal expansion load caused by freeze-thaw
  • r max and r min are the maximum and minimum pore sizes in the matrix
  • K, K L and K C are the matrix moduli of slurry, water and ice, respectively
  • ⁇ is the strain of slurry
  • b L and b C are the Biot coefficients of water and ice, respectively
  • ⁇ s is the thermal expansion coefficient of slurry
  • p atm is the plateau ambient air pressure
  • p atm0 is the ambient air pressure when pouring slurry
  • M is the calculation coefficient
  • S C , S L and S G are the volume fractions of ice, water and pores at the corresponding temperatures, respectively.
  • the internal expansion force generated by the expansion medium produced in the pores of the slurry due to the invasion and chemical reaction of corrosive ions such as sulfate in the plateau environment is solved according to the following steps: 1 Considering the effect of chemical reaction, solve the concentration distribution of different ions in the slurry; 2 Calculate the volume expansion force of chemical reaction based on the ion concentration distribution.
  • the specific c CA , c gpy are the concentrations of sulfate ion, calcium ion, calcium hydroxide, gypsum and calcium ion respectively, k, k 1 and k 2 are the chemical reaction coefficients, is the diffusion coefficient of sulfate ions and calcium ions, q is the concrete corrosion coefficient, is the calcium ion activity.
  • ps * is the equivalent load of internal expansion caused by sulfate attack
  • vAFt is the volume fraction of expanded ettringite, which is determined by the concentration calculated in step 1 combined with the chemical reaction equation.
  • the internal expansion force of other corrosive products such as magnesium salts in the slurry can be calculated according to their chemical reaction equations in combination with step 1.
  • ⁇ i is the corresponding environmental impact factor
  • pi * represents the environmental equivalent loads such as freeze-thaw, sulfate, and magnesium salt.
  • the step (4) solves the concrete numerical model considering the protection and repair functions of the plateau environment, which can be solved by using the finite element method.
  • the life span of the concrete is the life span when the steel bar begins to corrode.
  • the ion concentration at different depths is solved through steps (1-4), and the service life of the concrete is determined by comparing the critical concentration.
  • the steel bar corrosion repair material will increase the critical ion concentration of the steel bar, so the service life of the concrete is calculated as follows:
  • tc is the service life of concrete
  • xd is the buried depth of steel bars
  • frr is the action factor of steel bar corrosion repair materials
  • ccr is the inherent critical corrosion concentration of steel bars.
  • this embodiment provides a method for calculating the life of concrete in a plateau environment taking into account the protection and repair effects.
  • the specific process is as follows:
  • a concrete pier serving in a plateau environment in my country was selected.
  • the pier was in contact with water with a temperature range of -8 to 20°C and a chloride concentration of 20,000 mg/L. It was sulfate-free and did not bear additional external loads.
  • Different types of protective coatings green polyethylene coating CPE/chloroprene emulsion coating CR/chloroprene emulsion coating PVDC/chlorinated polyvinyl chloride coating CPVC
  • CPE/chloroprene emulsion coating CR/chloroprene emulsion coating PVDC/chlorinated polyvinyl chloride coating CPVC were used, as well as different crack damage repair materials (repair rate 50%/70%/90%) and different steel bar rust repair materials (critical concentration increased by 10%/30%).
  • chloride ion transmission is mainly carried by water level and there is adsorption and bonding inside the concrete, the moisture transmission rate is much higher than that of concrete.
  • the overall saturation inside the concrete is close to 1, but chloride ions only exist on the surface.
  • the chloride ion transmission depth is 8mm, 37mm, 34mm, 40mm and 48mm at 15 years, 30 years, 50 years and 100 years respectively.
  • the chloride ion concentration of concrete increases over time, and the growth trend changes from a sharp rise to a slow increase.
  • the use of protective coatings delays the corrosion time of chloride ions in concrete and slows down the diffusion rate of chloride ions in concrete.
  • the chloride ion concentration of concrete is closely related to the life of the protective coating. As the life of the protective coating increases, the time point when chloride ions begin to invade the concrete is gradually delayed, and the chloride ion concentration of the concrete also decreases linearly, indicating that the increase in the life of the protective coating can effectively reduce the chloride ion concentration contained in the concrete during its entire life cycle. Improving the life of the protective coating is an effective means to block and delay chloride ion corrosion and increase the service life of concrete.
  • the increase in the thickness of the protective coating can effectively reduce the final chloride ion concentration on the surface and inside of the concrete, and the reduction in the chloride ion concentration inside the concrete is more obvious than on the surface of the concrete.
  • the thickness of the protective coating is less than 1 mm, the time point when chloride ions begin to appear on the concrete surface is not delayed; and when the thickness of the protective coating exceeds 1 mm, the chloride ion concentration on the concrete surface begins to gradually increase. This shows that the thickness of the protective coating should be at least 1 mm to effectively block the medium from invading the concrete within the expected life of the coating, but even if the thickness of the protective coating gradually increases to 3 mm, chloride ions will still invade the concrete surface.
  • CPE chlorinated polyethylene coating
  • CR chloroprene emulsion coating
  • PVDC chloroprene emulsion coating
  • CPVC chlorinated polyvinyl chloride coating
  • the damage repair material has a repair rate of 70%
  • the chloride ion content at 30mm at 100 years is 73% of that at the unrepaired level.
  • the damage repair material has a damage repair rate of 90%
  • the chloride ion content can be reduced to 35% of that at the unrepaired level.
  • the change in the damage repair rate from 70% to 90% has little effect on the transmission of the corrosive medium within 5mm, because the damage is not completely repaired. Due to the suction effect of the solution in the surface cracks, the corrosive medium has already quickly penetrated into the concrete along the channel.
  • the repair rate of the repair material has greatly improved the reduction of the concentration of the corrosive medium within the range of 10 to 30mm.
  • the service life of concrete damaged by the environment is 50 years. If a 0.3 mm protective coating is used, the service life can be increased to only 56 years. If a 3 mm protective coating is used, the service life can be increased to 70 years.
  • the service life can reach 78 years when using a repair material with a damage repair rate of 80%. If a steel corrosion repair material that can increase the critical concentration by 10% is used, the service life can reach 63 years. If both types of repair materials are used at the same time, the concrete can be guaranteed to have a service life of 100 years.
  • this method can effectively calculate the service life of concrete considering protection and repair functions in plateau environments, and provide important guidance for engineering practice.

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Abstract

一种高原环境考虑防护与修复效果的混凝土寿命计算方法，包括：建立高原环境、荷载参数与时间的映射关系；构建混凝土几何模型，确定几何模型中各物相的材料属性；建立多因素耦合作用物理场方程，在混凝土几何模型的基础上设定边界条件和初始条件；求解混凝土内部温度、湿度、盐浓度、应力分布及其随时间的变化情况；计算混凝土内部的钢筋达到临界锈蚀浓度发生脱钝状态的时间，确定混凝土服役寿命；通过模拟不同高原环境下使用单一的表面防护涂层、裂缝修复材料和钢筋锈蚀修复材料或同时使用几类防护与修复材料后混凝土内部温度、湿度、应力响应和服役寿命，从而为高原环境下混凝土结构设计与施工提供依据。

Description

一种高原环境考虑防护与修复效果的混凝土寿命计算方法 技术领域
本发明属于混凝土服役寿命计算领域，特别是涉及一种高原环境考虑防护与修复效果的混凝土寿命计算方法。
背景技术
我国川藏铁路、青藏高速公路等国家重大交通工程正在往高原地区推进。该类工程区域具有最大28℃昼夜温差、30％-50％相对湿度、最低气温-32℃低温严寒、180天以上正负温交替高频冻融、盐浓度超标准上限数倍超盐渍土等极端环境特征。大温差、极端干燥、非饱和冻融与盐渍土的耦合作用，导致混凝土性能快速劣化、施工运维困难，对桥隧为主体的重大交通工程安全服役与耐久形成严峻挑战。表层防护、基体损伤修复与钢筋锈蚀修复是保障高频冻融、大温差、超盐渍土等高原环境下钢筋混凝土耐久性的重要途径。
目前，国内外学者开展了较多冻融、盐侵蚀、干湿交替环境下混凝土腐蚀劣化实验，收集氯离子、硫酸盐等离子浓度分布，从而预测混凝土服役寿命。然而，高原环境复杂，防护与修复材料种类多、性能参差不齐，现有研究方法对于单一高原环境下混凝土寿命计算不准确，无法适用于高原多因素耦合环境下的混凝土寿命计算，更无法计算考虑防护与修复作用的混凝土服役寿命。
发明内容
本发明的目的是提供一种高原环境考虑防护与修复效果的混凝土寿命计算方法，以解决现有方法无法计算高原环境下考虑防护与修复效果的混凝土服役寿命问题。
为实现上述目的，本发明提供了一种高原环境考虑防护与修复效果的混凝土寿命计算方法，包括以下步骤：
S1.确定模拟高原环境的温度、湿度、盐浓度和内、外力荷载作用情况，建立高原环境、荷载参数与时间的映射关系；
S2.构建高原环境下考虑防护与修复作用的混凝土几何模型，并确定所述几何模型中各物相的材料属性；
S3.建立温度-湿度-盐浓度-荷载多因素耦合作用物理场方程，在所述混凝土几何模型的基础上设定内部、外部边界条件和初始条件，其中，所述外部边界条件为所述高原环境、荷载参数与时间的映射关系；
S4.求解高原环境和荷载作用下考虑防护与修复作用的混凝土内部温度、湿度、盐浓度、应力分布及其随时间的变化情况；
S5.计算考虑防护与修复作用的混凝土内部的钢筋达到临界锈蚀浓度发生脱钝状态的时间，确定混凝土服役寿命。
可选的，所述S1中，所述高原环境、荷载参数与时间的映射关系，为固定不变或任意形式变化的温度、湿度、盐浓度和内、外力荷载；盐为侵蚀介质，包括：氯化钠、氯化钙、氯化铯、硫酸钠、硫酸镁；内、外力荷载包括：重力、内部孔隙膨胀力、外部荷载。
可选的，所述S2中，所述混凝土几何模型的构建过程为：采用蒙特卡洛方法随机生成混凝土细观结构，在混凝土表层添加任意厚度的防护涂层几何模型，所述防护涂层几何模型在1维结构中为与混凝土相连的线段，在2维模型中为与混凝土贴合的四面体，在3维结构模型中为与混凝土相贴合的六面体，损伤修复材料是均匀分布在水泥浆体内部的点阵或空间域；
可选的，所述S2中，所述混凝土几何模型包含粗骨料、细骨料和水泥浆体，粗细骨料级配类型可自由设置，骨料体积分数在0％～80％之间，混凝土表面防护涂层是粘附在混凝土表面的连续涂层，混凝土修复材料是以场域形式均匀分布在水泥浆体内部，产生损伤后自动触发修复作用，降低侵蚀介质传输速率并恢复混凝土力学性能。
可选的，所述S2中，所述物相包括：骨料、浆体、涂层；
所述浆体的材料属性包括：弹性模量、泊松比、密度、抗拉强度、断裂能、相变温度、相变温度间隔、相变潜热、导热系数、恒压热容、离子扩散系数、孔隙率、孔径分布；
所述涂层的材料属性包括：导热系数、恒压热容、离子扩散系数；
所述骨料和所述涂层的相关实验参数通过实验测试获得；所述浆体由砂和水泥浆体组成，浆体的参数由细观力学等效介质理论计算得到。
可选的，所述S3中，所述多因素耦合作用物理场方程包括：温度传导方程、水分传输方程、盐传输方程和力作用方程；
可选的，所述温度传导方程为：
其中，ρ为密度，C为比热容，T为温度，t为时间，λ为导热系数，L为相变潜热，θL为含水率；内部初始温度设定为与高原环境初始温度保持一致，边界条件选用dirichlet边界条件，与S1中确定的高原环境温度参数保持一致；
所述水分传输方程考虑了气态水和液态水的两项传输作用，表达如下：
其中，Pc为水分特征曲线，Ksl为饱和状态下水在材料中的渗透系数，为孔隙率，η为水的粘度，Krl为液相的相对渗透系数，Mw为水的摩尔质量，R为相对气体常数，ρl为水的密度，Dg0为水蒸气在空气中的自由扩散系数；Pgs为饱和蒸气压；
内部初始水分含量根据实际混凝土设定，范围在0～100RH％，边界条件选用dirichlet边界条件，与S1中确定的高原环境水分参数保持一致；
盐离子传输仅考虑对流和扩散两个作用，不考虑化学反应时，所述盐传输方程如下：
其中，c为盐离子浓度，D0为浆体中的基准离子扩散系数，t0为基准离子扩散系数测定的时间，m为时间依赖系数，θc为孔隙临界饱和度，U为混凝土中的离子活化能，Tref为基准离子扩散系数测定时的温度，d为损伤因子，由损伤力学能量法求得，fr为修复材料对损伤的修复率，Df为离子在水中的扩散系数，Rb为混凝土对离子的结合影响因子；内部初始离子浓度设定为0，边界条件选用dirichlet边界条件，与S1中确定的高原环境离子参数保持一致；
所述力作用方程如下：
其中，σ为应力，b为Biot系数，p*为环境作用等效荷载，所述环境作用等效荷载包括：冻融、硫酸盐因素引起的内膨胀等效荷载；



其中，pFT *为冻融引起的内膨胀荷载力，rmax和rmin为基体内最大和最小孔径，K、KL、KC分别为浆体、水和冰的基体模量，∈为浆体的应变，bL、bC分别为水和冰的Biot系数，αs为浆体的热膨胀系数，patm为高原环境气压，patm0为浇筑浆体时的环境气压，SC、SL、SG分别为对应温度下冰、水和气孔的体积分数，ps *为硫酸盐侵蚀引起的内膨胀等效荷载，vAFt为膨胀钙矾石体积分数，ωi为对应环境作用影响因子，pi *分别代表冻融、硫酸盐、镁盐环境等效荷载。
可选的，所述S5具体为：以钢筋开始锈蚀时的寿命为混凝土的最终服役寿命，通过步骤S1-S4求解不同深度处的离子浓度，对比临界浓度确定混凝土服役寿命，钢筋锈蚀修复材料会提高钢筋的临界离子浓度，因此混凝土服役寿命计算如下：
其中，tc为混凝土服役寿命，xd为钢筋埋置深度，frr为钢筋锈蚀修复材料作用因子，ccr为钢筋固有的锈蚀临界浓度。
本发明的技术效果为：
本发明可以模拟不同高原环境下使用单一的表面防护涂层、裂缝修复材料和钢筋阻锈材料或同时使用几类防护与修复材料后混凝土内部温度、 湿度、应力响应和服役寿命，从而为高原环境下混凝土结构设计与施工提供依据。
附图说明
构成本申请的一部分的附图用来提供对本申请的进一步理解，本申请的示意性实施例及其说明用于解释本申请，并不构成对本申请的不当限定。在附图中：
图1为本发明实施例中的为2维形式考虑防护与修复材料的几何模型示意图；
图2为本发明实施例中的使用不同类型防护涂层后混凝土表面0-5mm处侵蚀介质浓度分布情况示意图；
图3为本发明实施例中的使用不同类型防护涂层后钢筋埋置深度处侵蚀介质浓度分布情况示意图；
图4为本发明实施例中的使用不同厚度的防护涂层后混凝土内部的侵蚀介质浓度分布情况示意图；
图5为本发明实施例中的使用不同寿命的防护涂层后混凝土内部的侵蚀介质浓度分布情况示意图；
图6为本发明实施例中的使用修复率为50％的裂缝修复材料后混凝土内部的侵蚀介质浓度分布情况示意图；
图7为本发明实施例中的使用修复率为70％的裂缝修复材料后混凝土内部的侵蚀介质浓度分布情况示意图；
图8为本发明实施例中的使用修复率为90％的裂缝修复材料后混凝土内部的侵蚀介质浓度分布情况示意图；
图9为本发明实施例中的使用防护涂层后钢筋深度处的混凝土侵蚀介质浓度和临界浓度比较情况示意图；
图10为本发明实施例中的使用损伤修复材料和钢筋锈蚀修复后钢筋深度处的混凝土侵蚀介质浓度和临界浓度比较情况示意图。
具体实施方式
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。下面将参考附图并结合实施例来详细说明本申请。
本发明的目的是提供一种高原环境考虑防护与修复效果的混凝土寿命计算方法，解决现有方法无法计算高原环境下考虑防护与修复效果的混凝土服役寿命问题。
一种高原环境考虑防护与修复效果的混凝土寿命计算方法，包括以下步骤：
(1)确定模拟高原环境的温度、湿度、盐浓度和内、外力荷载作用情况，建立上述环境和荷载参数与时间的映射关系；
(2)构建考虑防护与修复作用的混凝土细观结构几何模型，并确定几何模型中各物相的材料属性；
(3)建立温度-湿度-盐浓度-荷载多因素耦合作用物理场方程，在步骤(2)建立的混凝土几何模型基础上设定内部、外部边界条件和初始条件，其中外部边界条件为步骤(1)中确定的高原环境和荷载参数与时间的映射关系；
(4)求解高原环境和荷载作用下考虑防护与修复作用的混凝土内部温度、湿度、盐浓度、应力分布及其随时间的变化情况；
(5)计算考虑防护与修复作用的混凝土内部的钢筋达到临界锈蚀浓度发生脱钝状态的时间，确定混凝土服役寿命。
其中，所述步骤(1)中环境和荷载参数与时间的映射关系，可以是固定不变的或任意形式变化的温度、湿度和外荷载作用。
所述步骤(2)中考虑防护与修复作用的混凝土几何模型，采用蒙特卡洛方法随机生成混凝土细观结构，在混凝土表层添加任意厚度的防护涂层几何模型，防护涂层几何模型在1维结构中为与混凝土相连的线段，在2维模型中为与混凝土贴合的四面体，在3维结构模型中为与混凝土相贴合的6面体。损伤修复材料是均匀分布在水泥浆体内部的点阵或空间域。
所述步骤(2)的考虑防护与修复作用的混凝土几何模型中存在骨料、浆体、涂层等物相，浆体需提供包括弹性模量、泊松比、密度、抗拉强度、断裂能、相变温度、相变温度间隔、相变潜热、导热系数、恒压热容、离子扩散系数、孔隙率、孔径分布等参数，涂层需提供导热系数、恒压热容、离子扩散系数。
其中，骨料和涂层的相关实验参数通过实验测试获得。由于浆体由砂和水泥浆体组成，因此是一种复合材料，浆体的参数由细观力学等效介质理论计算得到。
所述步骤(3)中的考虑防护与修复作用时，混凝土中的多因素耦合作用物理场方程包括温度传导方程、水分传输方程、盐传输方程和力作用方程。其中温度传导方程如下：
式中具体的ρ为密度，C为比热容，T为温度，t为时间，λ为导热系数， L为相变潜热，θL为含水率。
内部初始温度设定为与高原环境初始温度保持一致，边界条件选用dirichlet边界条件，与步骤(1)中确定的高原环境温度参数保持一致。
其中水分传输方程考虑了气态水和液态水的两项传输作用，如下所示：
式中具体的Pc为水分特征曲线，Ksl为饱和状态下水在材料中的渗透系数。为孔隙率，η为水的粘度，Krl为液相的相对渗透系数，Mw为水的摩尔质量，R为相对气体常数，ρl为水的密度，Dg0为水蒸气在空气中的自由扩散系数；Pgs为饱和蒸气压。
内部初始水分含量根据实际混凝土设定，范围在0～100RH％，边界条件选用dirichlet边界条件，与步骤(1)中确定的高原环境水分参数保持一致。
其中盐离子传输仅考虑对流和扩散两个作用，不考虑化学反应时，控制方程如下：
式中具体的c为盐离子浓度，D0为浆体中的基准离子扩散系数，t0为基准离子扩散系数测定的时间，m为时间依赖系数，θc为孔隙临界饱和度，U为混凝土中的离子活化能，Tref为基准离子扩散系数测定时的温度，d为损伤因子，由损伤力学能量法求得，fr为修复材料对损伤的修复率，Df为离子在水中的扩散系数，Rb为混凝土对离子的结合影响因子。
内部初始离子浓度设定为0，边界条件选用dirichlet边界条件，与步骤(1)中确定的高原环境离子参数保持一致。
其中力作用方程如下：
式中具体的σ为应力，b为Biot系数，p*为环境作用等效荷载，在高原环境中，主要包括冻融、硫酸盐等因素引起的内膨胀等效荷载。
其中，高原环境下由冻融引起的内膨胀等效荷载按下列步骤求解：①先确定特定温度下的浆体孔隙中气态、液态和冰晶的含量；②依据气态、液态和冰晶含量求解计算内膨胀荷载。
①步骤计算按下式进行：



式中具体的rc为对应温度下的临界冻结孔径，γCL为水冰界面能，Σm为水冰相变熵，ΔT为高原环境下实际温度与对应高原气压环境下溶液冰点的温度差，受高原气压、孔隙等影响，δ为孔壁边水膜厚度，厚度通过非饱和C-S-H凝胶孔中水分分布的分子动力学模拟获得，Sl0(r)、SC(r)、SL(r)分别为对应孔径下初始液态水饱和度函数、冰晶饱和度函数和液态水饱和度函数，SG为浆体孔隙中气体饱和度，rsc为临界饱和孔隙同样由分子动力学模拟获取，为孔径小于rsc的孔隙率。
②步骤计算按下式进行：


式中具体的pFT *为冻融引起的内膨胀荷载力，rmax和rmin为基体内最大和最小孔径，K、KL、KC分别为浆体、水和冰的基体模量，∈为浆体的应变，bL、bC分别为水和冰的Biot系数，αs为浆体的热膨胀系数，patm为高原环境气压，patm0为浇筑浆体时的环境气压，M为计算系数，SC、SL、SG分别为对应温度下冰、水和气孔的体积分数。
其中，高原环境下由硫酸盐等侵蚀性离子侵入并发生化学反应，在浆体孔隙中产生膨胀性侵蚀介质产生的内膨胀力按下列步骤求解：①考虑化学反应作用，求解不同离子在浆体中的浓度分布；②依据离子浓度分布，计算化学反应体积膨胀力。
①以硫酸盐侵蚀步骤计算按下式进行：



式中具体的cCA、cgpy、分别为硫酸根离子、钙离子、氢氧化钙、石膏和钙离子的浓度，k、k1、k2为化学反应系数，为硫酸根离子和钙离子扩散系数，q为混凝土腐蚀系数，为钙离子活度。
②步骤计算按下式进行：

式中具体的ps *为硫酸盐侵蚀引起的内膨胀等效荷载，vAFt为膨胀钙矾石体积分数，由步骤①中计算浓度结合化学反应方程确定。
其他镁盐等腐蚀性产物在浆体中的内膨胀力可按其化学反应方程，结合步骤①进行计算。
当高原环境同时存在冻融和硫酸盐等侵蚀介质作用时，浆体所受最终的内膨胀荷载计算如下：
式中具体的ωi为对应环境作用影响因子，pi *分别代表冻融、硫酸盐、镁盐等环境等效荷载。
所述步骤(4)求解上述高原环境考虑防护与修复作用的混凝土数值模型，可采用有限元法进行求解。
所述步骤(5)以钢筋开始锈蚀时的寿命为混凝土的最终服役寿命。通过步骤(1-4)求解不同深度处的离子浓度，对比临界浓度确定混凝土服役寿命。钢筋锈蚀修复材料会提高钢筋的临界离子浓度，因此混凝土服役寿命计算如下：
式中具体的tc为混凝土服役寿命，xd为钢筋埋置深度，frr为钢筋锈蚀修复材料作用因子，ccr为钢筋固有的锈蚀临界浓度。
实施例一
如图1-10所示，本实施例中提供一种高原环境考虑防护与修复效果的混凝土寿命计算方法，具体过程如下：
选择我国一处服役于高原环境的混凝土墩柱，墩柱接触水，温度范围为-8～20℃，氯盐浓度为20000mg/L，无硫酸盐，不承受额外的外荷载作用，使用不同类型的防护涂层(绿化聚乙烯涂层CPE/氯丁乳液涂层CR/氯偏乳液涂层PVDC/氯化聚氯乙烯涂层CPVC)，使用不同裂缝损伤修复材料(修复率50％/70％/90％)，使用不同的钢筋锈蚀修复材料(临界浓度提高10％/30％)。
依据步骤(1-4)构建高原环境下考虑防护作用的数值模型(图1)，并求解获得各参数在混凝土中的分布情况，以最易引起钢筋锈蚀的氯离子浓度为例(图2-8)。
由图2可知，在2年内，水分和离子均未穿过防护涂层，在第5年时， 混凝土表层骨料较少的局部区域中出现了少量水分和氯离子，但在防护涂层生效的10年内，混凝土内部并未出现大量的水分和氯离子，这也表明了在防护涂层的使用寿命内防护涂层可有效隔绝水和离子的作用，直接提高混凝土抗侵蚀性能。在防护涂层的失效后，相当于水分和氯离子直接接触了混凝土表面，随即混凝土内部的水分和氯离子含量大幅增加。由于氯离子传输主要以水位载体，且混凝土内部存在吸附结合作用，水分传输速率远超过混凝土，在30年时，混凝土内部的整体饱和度接近于1，但氯离子仅在表层存在。使用服役寿命为10年的表层防护涂层，在15年、30年、50年、100年时，氯离子传输深度分别为8mm、37mm、34mm、40mm和48mm。
由图3可知，混凝土氯离子浓度随时间的推移而不断增长，且增长趋势由急剧上升到缓慢提高。防护涂层的使用推迟了混凝土中氯离子的侵蚀时间点，延缓了氯离子在混凝土中的扩散速度。混凝土氯离子浓度与防护涂层寿命密切相关。随着防护涂层寿命的增加，混凝土中氯离子开始侵入的时间点逐渐被推迟，混凝土氯离子浓度也呈线性下降，表明防护涂层寿命的增加可有效降低混凝土使用过程全寿命周期中所含的氯离子浓度，提高防护涂层的寿命是阻隔延缓氯离子侵蚀和提高混凝土服役寿命的有效手段。
由图4可知，防护涂层厚度的增加可以有效降低混凝土表面以及内部最终的氯离子浓度，且对混凝土内部氯离子浓度的降低比混凝土表面更加明显。当防护涂层厚度在1mm以内时，混凝土表面开始出现氯离子的时间点并没有被推迟；而当防护涂层厚度超过1mm时，混凝土表面氯离子浓度才开始逐渐上升。表明防护涂层厚度至少应在1mm以上时才可在涂层预期寿命内有效阻隔介质侵入混凝土中，但即使防护涂层厚度逐渐增加至3mm，依然会存在氯离子侵入混凝土表面。
由图5可知，与未使用防护涂层相比，使用氯化聚乙烯涂层(CPE)、氯丁乳液涂层(CR)、氯偏乳液涂层(PVDC)和氯化聚氯乙烯涂层(CPVC)四种防护涂层对混凝土的最终氯离子浓度分别降低了86％、40％、70％和84％。其中，CPE、CR、PVDC和CPVC四种防护涂层均可有效延缓混凝土氯离子侵入时间，降低混凝土内部氯离子浓度，提高混凝土服役寿命。
由图6-8可知，损伤修复材料的修复率为70％时，对于100年时30mm处的氯离子含量为未修复时的73％，损伤修复材料的损伤修复率为90时，可将氯离子含量降低至未修复时的35％。但损伤修复率从70％～90％的变化，对于5mm内的侵蚀介质传输影响不大，因为并未完全修复损伤，由于溶液在表层裂纹中的抽吸作用，侵蚀介质随着通道早已快速侵入混凝土内部。修复材料的修复率对于10～30mm范围内的侵蚀介质浓度降低有较大提高。
分别考虑防护涂层、损伤修复材料和钢筋锈蚀修复材料的作用效应，依据步骤(5)求解混凝土服役寿命(图9-10)。
由图9可知，由环境引发损伤的混凝土服役寿命为50年，若使用0.3mm的防护涂层后，寿命可提高只56年，若使用3mm的防护涂层后，寿命可提高至70年。
由图10可知，对于不使用防护材料的混凝土，考虑损伤修复效应和锈蚀修复效应，使用损伤修复率为80％的修复材料下，可达到78年服役寿命，若使用可使临界浓度提高10％的钢筋锈蚀修复材料时，服役寿命可达63年，若同时使用两类修复材料，可保障混凝土达到100年的服役寿命。
因此，本方法可有效计算高原环境下考虑防护与修复作用的混凝土服役寿命，为工程实践提供重要的指导作用。
以上所述，仅为本申请较佳的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应该以权利要求的保护范围为准。

Claims (8)

  1. 一种高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，包括以下步骤：
    S1.确定模拟高原环境的温度、湿度、盐浓度和内、外力荷载作用情况，建立高原环境、荷载参数与时间的映射关系；
    S2.构建高原环境下考虑防护与修复作用的混凝土几何模型，并确定所述几何模型中各物相的材料属性；
    S3.建立温度-湿度-盐浓度-荷载多因素耦合作用物理场方程，在所述混凝土几何模型的基础上设定内部、外部边界条件和初始条件，其中，所述外部边界条件为所述高原环境、荷载参数与时间的映射关系；
    S4.求解高原环境和荷载作用下考虑防护与修复作用的混凝土内部温度、湿度、盐浓度、应力分布及其随时间的变化情况；
    S5.计算考虑防护与修复作用的混凝土内部的钢筋达到临界锈蚀浓度发生脱钝状态的时间，确定混凝土服役寿命。
  2. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S1中，所述高原环境、荷载参数与时间的映射关系，为固定不变或任意形式变化的温度、湿度、盐浓度和内、外力荷载；盐为侵蚀介质，包括：氯化钠、氯化钙、氯化铯、硫酸钠、硫酸镁；内、外力荷载包括：重力、内部孔隙膨胀力、外部荷载。
  3. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S2中，所述混凝土几何模型的构建过程为：采用蒙特卡洛方法随机生成混凝土细观结构，在混凝土表层添加任意厚度的防护涂层几何模型，所述防护涂层几何模型在1维结构中为与混凝土相连的线段，在2维模型中为与混凝土贴合的四面体，在3维结构模型中为与混凝土相贴合的六面体，损伤修复材料是均匀分布在水泥浆体内部的点阵或空间域。
  4. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S2中，所述混凝土几何模型包含粗骨料、细骨料和水泥浆体，粗细骨料级配类型可自由设置，骨料体积分数在0％～80％之间，混凝土表面防护涂层是粘附在混凝土表面的连续涂层，混凝土修复材料以场域形式均匀分布在水泥浆体内部。
  5. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S2中，所述物相包括：骨料、浆体、涂层；
    所述浆体的材料属性包括：弹性模量、泊松比、密度、抗拉强度、断裂能、相变温度、相变温度间隔、相变潜热、导热系数、恒压热容、离子扩散系数、孔隙率、孔径分布；
    所述涂层的材料属性包括：导热系数、恒压热容、离子扩散系数；
    所述骨料和所述涂层的参数通过实验测试获得；所述浆体由砂和水泥浆体组成，浆体的参数由细观力学等效介质理论计算得到。
  6. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S3中，所述多因素耦合作用物理场方程包括：温度传导方程、 水分传输方程、盐传输方程和力作用方程。
  7. 根据权利要求6所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述温度传导方程为：
    其中，ρ为密度，C为比热容，T为温度，t为时间，λ为导热系数，L为相变潜热，θL为含水率；
    内部初始温度设定为与高原环境初始温度保持一致，边界条件选用dirichlet边界条件，与S1中确定的高原环境温度参数保持一致；
    所述水分传输方程考虑了气态水和液态水的两项传输作用，表达如下：
    其中，Pc为水分特征曲线，Ksl为饱和状态下水在材料中的渗透系数，为孔隙率，η为水的粘度，Krl为液相的相对渗透系数，Mw为水的摩尔质量，R为相对气体常数，ρl为水的密度，Dg0为水蒸气在空气中的自由扩散系数；Pgs为饱和蒸气压；
    内部初始水分含量根据实际混凝土设定，范围在0～100RH％，边界条件选用dirichlet边界条件，与S1中确定的高原环境水分参数保持一致；
    盐离子传输仅考虑对流和扩散两个作用，不考虑化学反应时，所述盐传输方程如下：
    其中，c为盐离子浓度，D0为浆体中的基准离子扩散系数，t0为基准离子扩散系数测定的时间，m为时间依赖系数，θc为孔隙临界饱和度，U为混凝土中的离子活化能，Tref为基准离子扩散系数测定时的温度，d为损伤因子，由损伤力学能量法求得，fr为修复材料对损伤的修复率，Df为离子在水中的扩散系数，Rb为混凝土对离子的结合影响因子；
    内部初始离子浓度设定为0，边界条件选用dirichlet边界条件，与S1中确定的高原环境离子参数保持一致；
    所述力作用方程如下：
    其中，σ为应力，b为Biot系数，p*为环境作用等效荷载，所述环境作用等效荷载包括：冻融、硫酸盐因素引起的内膨胀等效荷载；



    其中，pFT *为冻融引起的内膨胀荷载力，rmax和rmin为基体内最大和最小孔径，K、KL、KC分别为浆体、水和冰的基体模量，∈为浆体的应变，bL、bC分别为水和冰的Biot系数，αs为浆体的热膨胀系数，patm为高原环境气压，patm0为浇筑浆体时的环境气压，SC、SL、SG分别为对应温度下冰、水和气孔的体积分数，ps *为硫酸盐侵蚀引起的内膨胀等效荷载，vAFt为膨胀钙矾石体积分数，ωi为对应环境作用影响因子，pi *分别代表冻融、硫酸盐、镁盐环境等效荷载。
  8. 根据权利要求1所述的高原环境考虑防护与修复效果的混凝土寿命计算方法，其特征在于，
    所述S5具体为：以钢筋开始锈蚀时的寿命为混凝土的最终服役寿命，通过S1-S4求解不同深度处的离子浓度，对比临界浓度确定混凝土服役寿命，混凝土服役寿命计算如下：
    其中，tc为混凝土服役寿命，xd为钢筋埋置深度，frr为钢筋锈蚀修复材料作用因子，ccr为钢筋固有的锈蚀临界浓度。
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