Revision of Ver.7.4.1 Revision of Ver.7.4.1
Function
Define Compressive Strength of concrete or the change of modulus of elasticity to reflect the variation of modulus of elasticity with time.
The concrete age of each member is measured from the time the concrete is cast, and each member will have an appropriate compressive strength and modulus of elasticity at each construction stage.
If concrete is poured into different parts of a composite section in stages, the difference in compressive strength and modulus of elasticity of each part, due to the difference in concrete age of each part, can be considered.
To reflect the change in compressive strength of concrete or the change in modulus of elasticity, 'Variation of Comp. Strength' option should be checked in Construction Stage Analysis Control Data.
Call
From the Main Menu select Model > Properties > Time Dependent Material (Comp. Strength).
Select Geometry > Properties > Time Dependent Material (Comp. Strength) in the Menu tab of the Tree Menu.
Click -Time_Dependent_Material-comp.str(i).jpg)
Time Dependent Material (Comp. Strength) in the Property Tool Bar.
Entry
-Time_Dependent_Material-comp.str(d).jpg)
Click -Add(b).jpg)
to define a new time
variant modulus of elasticity (Comp. strength). Click -Modify(b).jpg)
and
-delete(b).jpg)
to change and delete the data previously entered. Click
.jpg)
to copy previously entered data.
-Add_Modify_Time_Dependent_M(Comp.S).jpg)
NameEnter the name of function defining the time variant modulus of elasticity (Comp. strength) of concrete.
TypeSelect Code to define the time dependent compressive strength of concrete, or directly specify the numerical values defining the function.
Development of StrengthWhen Code is selected in Type, the change of modulus of elasticity is defined by the change of compressive strength.
Code
Select a code defining the change of compressive strength of concrete.
Where
ACI Code is selected
Specify the Concrete Compressive Strength
at 28 Days (f28)
and Concrete Compressive Strength Factors (a, b).
Note 1
Modulus of elasticity, which will be reflected in the analysis, is calculated using the compressive strength of concrete and weight density.
Revision of Ver.7.4.1
Note 2
Modulus of elasticity, which will be reflected in the analysis, is calculated from the equation below and can be checked in the Results>Result tables>Construction Stage>Element Properties at Each Stage.
-1.jpg)
(in MPa)
-2.jpg)
: Density of concrete, kg/m3
-3.jpg)
: Compressive strength of concrete, MPa
Where
CEB-FIP is selected
Specify the Concrete Compressive Strength at 28 Days (fck) and Cement Type (s).
RS: Rapid hardening high strength cements
N, R: Normal or rapid hardening cements
SL:
Slowly hardening cements
Where
Ohzagi is selected
The equation proposed by Ohzagi is used to define the change of compressive strength of concrete. Specify the Concrete Compressive Strength at 28 Days (S28) and Cement Type Factors (a, b & c).
RS: Rapid hardening high strength cements
N, R: Normal or rapid hardening cements
SL: Slowly hardening cements
Fly ash:
Fly ash cementing material
-AddModify_Time_Dependent_Material(user).jpg)
Where User
is selected, enter the modulus of elasticity varying with time under Time
and Elasticity in the table.
-Redraw_Graph(b).jpg)
: Produce
a graph based on the entered data.
Note 1
If User is selected, the entered compressive strength and tensile strength
do not affect general analysis, but they are reflected only for the calculation
of crack index in heat of hydration analysis.
Note
2
The user may directly input all of modulus of elasticity, compressive strength
and tensile strength.
Scale FactorEnter a multiplier to apply to the values for modulus of elasticity if User Type is assigned.
Graph OptionsCheck on for Log Scale graph.
Graph TypeThe Y-axis of the graph can represent compressive strength, tensile strength or modulus of elasticity.