ConcreteMoistureDehydration

Source term for dehydrated water for moisture transfer in concrete.

Description

This kernel provides a source term accounting for dehydrated water in the governing equation for moisture in concrete. The amount of dehydrated water, $var element = document.getElementById("moose-equation-482272f2-afb3-4dca-be7a-a0c6a3b66631");katex.render("W_d", element, {displayMode:false,throwOnError:false});$ , in units of (g water)/(g material)/(cm $var element = document.getElementById("moose-equation-77dbc1d6-a3e1-4ecc-bde2-7080f73bb77f");katex.render("^3", element, {displayMode:false,throwOnError:false});$ volume of material), represents the water molecules released into concrete pores due to dehydration of hydrated minerals within cement paste as the temperature in concrete increases. $var element = document.getElementById("moose-equation-79b252f4-9977-4f6f-8e74-c8d513ba71d1");katex.render("W_d", element, {displayMode:false,throwOnError:false});$ is given by the following empirical formula:

(1)var element = document.getElementById("moose-equation-26666448-06c8-4148-8bd8-f27ab8d12761");katex.render("W_d = W_H^{105}f_d(T),", element, {displayMode:true,throwOnError:false});

in which $var element = document.getElementById("moose-equation-dada8907-8935-44b9-b543-e6b4a9989a86");katex.render("W_H^{105}", element, {displayMode:false,throwOnError:false});$ is the hydrated water content (in units of (g water)/(g material)/(cm $var element = document.getElementById("moose-equation-b322cb3d-a736-4756-a608-75b1bed208fb");katex.render("^3", element, {displayMode:false,throwOnError:false});$ volume of material)) at 105 $var element = document.getElementById("moose-equation-32aae6a3-874c-4bb8-90a4-5a11abe9ac88");katex.render("\\degree", element, {displayMode:false,throwOnError:false});$ C, and $var element = document.getElementById("moose-equation-61194596-3ad1-4eb3-a98a-32e28a5d7c1b");katex.render("f_d", element, {displayMode:false,throwOnError:false});$ is a function of the weight loss of the concrete due to heat. Dehydration of hydrated minerals within cement paste typically begins at about 120 $var element = document.getElementById("moose-equation-5904617a-cc39-4d2a-a0b2-dc4034a0eb6d");katex.render("\\degree", element, {displayMode:false,throwOnError:false});$ C.

The function describing variation of $var element = document.getElementById("moose-equation-8b816ce7-f107-4cb4-99b5-013953855f5f");katex.render("W_H", element, {displayMode:false,throwOnError:false});$ over time is given by

(2)var element = document.getElementById("moose-equation-3ebb9d39-b428-4157-9a29-d7bf19521199");katex.render("\\begin{array}{lll} W_H(t_e) = 0.21c(\\frac{t_e}{\\tau_e + t_e}), & \\tau_e = 23 & \\textrm{days} \\end{array}", element, {displayMode:true,throwOnError:false});

where $var element = document.getElementById("moose-equation-a9e07956-d4bd-4ef1-b0f9-c28b48b493a9");katex.render("c", element, {displayMode:false,throwOnError:false});$ is mass of (anhydrous) cement per cm $var element = document.getElementById("moose-equation-6713c4b1-a037-4b90-b8a5-c4cf04eefef2");katex.render("^3", element, {displayMode:false,throwOnError:false});$ of concrete and $var element = document.getElementById("moose-equation-bf8eed2e-636f-4599-990b-07532cc17586");katex.render("t_e", element, {displayMode:false,throwOnError:false});$ is the equivalent hydration period, which is given by

(3)var element = document.getElementById("moose-equation-39d7330e-fc4a-4ed6-ab5e-b31b7d878d93");katex.render("t_e = \\int \\beta_H\\beta_Tdt \\\\ \\beta_H(H) = \\frac{1}{1+(3.5-3.5H)^4} \\\\ \\beta_T(T) = e^{\\frac{Q_h}{R}(\\frac{1}{T_{ref}}-\\frac{1}{T})}", element, {displayMode:true,throwOnError:false});

where

$var element = document.getElementById("moose-equation-7289c44a-5c96-494b-ad16-0f463f8f4b3f");katex.render("t", element, {displayMode:false,throwOnError:false});$ = actual time
$var element = document.getElementById("moose-equation-4343eb7a-551f-4b0a-ba3b-28475abbfc2a");katex.render("Q_h", element, {displayMode:false,throwOnError:false});$ = activation energy of hydration
$var element = document.getElementById("moose-equation-c32271f5-179b-484e-ac1e-8dc3f751b13a");katex.render("\\frac{Q_h}{R}", element, {displayMode:false,throwOnError:false});$ = 2700 K

Typical values of $var element = document.getElementById("moose-equation-a016dc58-99fd-4050-a5c1-bb9e46c458ec");katex.render("f_d(T)", element, {displayMode:false,throwOnError:false});$ are plotted by Harmathy and Allen (1973). In this implementation, a simple linear function

(4)var element = document.getElementById("moose-equation-f0973f74-36a7-4247-9c0e-73eae876b29e");katex.render("f_d(T) = \\frac{0.05T}{600},", element, {displayMode:true,throwOnError:false});

is used to account for mass loss of concrete due to dehydration. It should be noted that $var element = document.getElementById("moose-equation-a9272f55-bb34-409e-b526-765c5100c4e9");katex.render("W_d", element, {displayMode:false,throwOnError:false});$ is often negligible in modeling moisture diffusion under most circumstances unless the concrete is subjected to rapid heating conditions at high temperature. It is also interesting to note that by extending the definition of $var element = document.getElementById("moose-equation-0e486f2d-1c78-47ec-ad9f-65eef4b6e3d9");katex.render("W_d", element, {displayMode:false,throwOnError:false});$ to hydrated water, the same model can also be applied to simulate the moisture distribution in concrete during the curing process. In such case, $var element = document.getElementById("moose-equation-b9ec74d3-151c-4d5b-b799-c0dea9095f42");katex.render("W_d", element, {displayMode:false,throwOnError:false});$ becomes a sink term and represents the loss of free water molecules in pores due to hydration reactions.

The material properties used by this model are computed by the ConcreteThermalMoisture material.

Input Parameters

variableThe name of the variable that this residual object operates on
C++ Type:NonlinearVariableName
Options:
Description:The name of the variable that this residual object operates on

Required Parameters

blockThe list of block ids (SubdomainID) that this object will be applied
C++ Type:std::vector<SubdomainName>
Options:
Description:The list of block ids (SubdomainID) that this object will be applied
dehydration_start_temperature120themprature threshold for dehydartion of cement
Default:120
C++ Type:double
Options:
Description:themprature threshold for dehydartion of cement
displacementsThe displacements
C++ Type:std::vector<VariableName>
Options:
Description:The displacements
lumpingFalseTrue for mass matrix lumping, false otherwise
Default:False
C++ Type:bool
Options:
Description:True for mass matrix lumping, false otherwise
property_namehydrated_waterThe water chemically bonded to hydrates
Default:hydrated_water
C++ Type:std::string
Options:
Description:The water chemically bonded to hydrates
temperaturenonlinear variable name for temperature in unit of Celscius
C++ Type:std::vector<VariableName>
Options:
Description:nonlinear variable name for temperature in unit of Celscius

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
diag_save_inThe name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Options:
Description:The name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Options:
Description:Determines whether this object is calculated using an implicit or explicit form
save_inThe name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Options:
Description:The name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Options:
Description:The seed for the master random number generator
use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Options:
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector<TagName>
Options:
Description:The extra tags for the matrices this Kernel should fill
extra_vector_tagsThe extra tags for the vectors this Kernel should fill
C++ Type:std::vector<TagName>
Options:
Description:The extra tags for the vectors this Kernel should fill
matrix_tagssystem timeThe tag for the matrices this Kernel should fill
Default:system time
C++ Type:MultiMooseEnum
Options:nontime, system, time
Description:The tag for the matrices this Kernel should fill
vector_tagstimeThe tag for the vectors this Kernel should fill
Default:time
C++ Type:MultiMooseEnum
Options:nontime, time
Description:The tag for the vectors this Kernel should fill

Tagging Parameters

References

TZ Harmathy and LW Allen. Thermal properties of selected masonry unit concretes. In ACI Journal Proceedings, volume 70. ACI, 1973.

@inproceedings{harmathy1973thermal,
    Author = "Harmathy, TZ and Allen, LW",
    Booktitle = "ACI Journal Proceedings",
    Number = "2",
    Organization = "ACI",
    Title = "Thermal properties of selected masonry unit concretes",
    Volume = "70",
    Year = "1973"
}

Description
Input Parameters
References