What is chloride diffusion coefficient?
The chloride diffusion coefficient is an indication of the capacity of any type of concrete to resist chloride penetration and is used to predict the service life of reinforced concrete structures.
What is the diffusion rate of chlorine?
0.650 : 1
Thus, the relative rate of diffusion for the chlorine and ethane gas is 0.650 : 1.
What is chloride diffusion?
Chloride diffusivity is a complex phenomenon, as the movement of chloride ions through the concrete is slowed down by other ions present in the pore solution of concrete. Therefore, convenient determination of the chloride diffusion coefficients of concrete is rather difficult.
What is chloride ion diffusion in concrete?
In saturated state, chloride ions enter concrete by ionic diffusion due to concentration gradient between the exposed surface and the pore solution inside concrete. This process is often described by Fick’s second law of diffusion [8.
What is diffusion coefficient of concrete?
Diffusion coefficient D, is considered the rate determining parameter of chloride ingress in concrete. In the paper D is defined following Crank and emphasis is made in that different D values are obtained from different testing conditions and from the units in which chloride concentration is expressed.
What is liquid diffusion?
In liquids, molecular diffusion occurs by jumps of the molecules from one position to another; this arises when the energy of the molecule is high enough to rupture the bonds with the neighboring molecules allowing the molecule to move.
What is the coefficient of chlorine?
2”
Because chlorine is diatomic, there are two chlorines in the reactants and there must also be two chlorines in the products. In order to accomplish this, we place the coefficient “2” in front of the product, NaCl.
How do you calculate diffusion rate?
Key Equations
- rate of diffusion=amount of gas passing through an areaunit of time.
- rate of effusion of gas Arate of effusion of gas B=√mB√mA=√MB√MA.
What causes chloride diffusion?
As shown in Figure 1, at a certain depth inside concrete, the chloride concentration increases with time. On the other hand, at a higher depth from the surface, the chloride ion concentration is lower and therefore there is higher concentration gradient that causes a higher coefficient of chloride diffusion.
What is Fick’s Law of Diffusion equation?
Fick’s First Law Movement of solute from higher concentration to lower concentration across a concentration gradient. J=−Ddφdx. Where, J: diffusion flux. D: diffusivity.