## 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,

1. "Variation of Comp. Strength" option should be checked in Construction Stage Analysis Control Data.

2. Assign the defined elasticity change characteristics from the "Time Dependent Material Link" to a specific material.

## Call

From the main menu, select **[Properties] tab > [Material Properties] group > [Time Dependent] > ****[Comp. Strength]**

## Input

Fig. Time Dependent Material (Comp. Strength) dialog box

To redefine the variation of elastic modulus (compressive strength) of concrete over time,

### Add

Add new content

### Modify

Modify the entered content

### Delete

Delete the entered content

Fig. Add/Modify Time-Dependent Material (Comp. Strength)

### Name

Enter the name of the function defining the time-variant modulus of elasticity (Comp. strength) of concrete.

### Type

Select Code to define the time-dependent compressive strength of concrete, or directly specify the numerical values defining the function.

**Code**: Define the variation of compressive strength of concrete according to the design standards.

**User**: The user directly inputs the variations of elastic modulus, compressive strength, and tensile strength.

### Development of Strength

When Code is selected in Type, the change of modulus of elasticity is defined by the change of compressive strength.

**Where ACI Code is selected**

Specify the Concrete Compressive Strength at 28 Days (f28) and Concrete Compressive Strength Factors (a, b).

**Note1**

The modulus of elasticity, which will be reflected in the analysis, is calculated using the compressive strength of concrete and weight density.

**Note2**

The 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>Elem CEB-FIP(2010) is selected

**Where CEB-FIP(1990) is selected**

**Wherestrong **

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

**Where INDIA(IRC:18-2000) is selected**

The following equation is used to define the change of compressive strength of concrete. Specify the Concrete Compressive Strength at 28 Days (S28).

**Where European is selected**

Specify the mean value of Concrete Compressive Strength at 28 Days (fck+delta_f) and Cement Type (s).

RS: Rapid hardening high strength cements

N, R: Normal or rapid hardening cements

SL: Slowly hardening cements

**Where CEB-FIP(1978) is selected**

Specify the Concrete Compressive Strength at 28 Days (fck) and Cement Type (s).

**Where AS 3600-2009 is selected**

Specify the Concrete Compressive Strength at 28 Days (fck).

**Note 1**

Mean modulus of elasticity of concrete at the appropriate age is calculated as follows.

**Note 2**

Since there is no equation for Compressive Strength at the appropriate age in Australian Standard, it is calculated based on the following equation specified in CEB-FIP1978.

**Where AS/RTA 5100.5-2011 is selected**

Specify the Concrete Compressive Strength at 28 Days (fck).

**Note 1**

Mean modulus of elasticity of concrete at the appropriate age is calculated as follows.

**Note 2**

Since there is no equation for Compressive Strength at the appropriate age in Australian Standard, it is calculated based on the following equation specified in CEB-FIP1978.

**Where 'GILBERT AND RANZI' is selected**

Specify the mean in-situ compressive strength of concrete at 28 days (fcmi)

Modulus of elasticity

ρ: Weight density

Modulus of elasticity with time

s: Cement Type

Ordinary Portland cement, s=0.38

High early strength cement, s=0.25

### Graph Options

Convert the X-axis or Y-axis of the graph to a logarithmic scale.

### Graph Type

Specify the Y-axis of the graph as compressive strength, tensile strength, or elastic modulus.