# Materials

This section defines material properties for concrete, reinforcement steel, structural steel, and prestressing steel.

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**Navigation:** Properties > Materials

For detailed parameter explanations, see the [Materials Reference](https://docs.openbrim.org/templates/concrete-u-girder-bridge-workflow/properties-cug/materials-cug).
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## Steps

### Step 1: Navigate to Materials

Navigate to **Properties > Materials** in the tree view.

![Navigation](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-134022.png?api=v2)

### Step 2: Import Steel Materials

Click the **three-dots icon** on the first cell of Name and select **Import Material**.

Import the following steel materials from OpenBrIM Library:

| Material Path                                                                | Material Name |
| ---------------------------------------------------------------------------- | ------------- |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Reinforcement Steel | A615\_60      |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Structural Steel    | A709\_50W     |

![Import Steel](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-134517.png?api=v2)

![Select Material](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-134808.png?api=v2)

![Material Selected](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-135135.png?api=v2)

### Step 3: Import Concrete Materials

Import the following concrete materials:

| Material Path                                                         | Material Name |
| --------------------------------------------------------------------- | ------------- |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_3\_1/2ksi |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_4ksi      |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_5ksi      |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_6ksi      |

### Step 4: Import Prestressing Steel

Import the prestressing steel material:

| Material Path                                                               | Material Name           |
| --------------------------------------------------------------------------- | ----------------------- |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Prestressing Steel | Grade270\_lowrelaxation |

<details>

<summary><strong>Quick Tip:</strong> Stress-Strain Curves</summary>

Each material type comes with a default stress-strain curve for section capacity calculations. To view or customize:

1. Click the **three-dots icon** on **A615\_60** and select **Edit**
2. Click on **Stress/Strain Model** dropdown to modify parameters
3. The **Stress/Strain Curve** updates automatically based on the selected model

![Stress-Strain Model](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-140331.png?api=v2)

![Curve Options](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-141043.png?api=v2)

</details>

### Step 5: Create Rigid Material

Add a new row and enter **RigidMaterial** as the name.

{% hint style="warning" %}
Set the **unit weight** of rigid materials to **0** as a general practice.
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![Rigid Material](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-144128.png?api=v2)

## Verification

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After completing these steps, the material definitions should appear as shown below.
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![Completed Materials](https://openbrim.atlassian.net/wiki/download/attachments/2258927617/image-20230824-144251.png?api=v2)