# Materials
This section defines material properties for structural steel, reinforcing steel, and concrete used in the Steel I Girder Bridge model.
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**Navigation:** Properties > Materials
For detailed parameter explanations, see the [Materials Reference](https://docs.openbrim.org/templates/steel-i-girder-bridge-workflow/properties-sig/materials-sig).
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## Steps
### Step 1: Navigate to Materials
Navigate to **Properties > Materials** in the tree view.
### Step 2: Import Structural Steel Materials
Click the **three-dots icon** on the first cell under **Name** and select **Import Material**.
Import the following steel materials from the OpenBrIM Library:
| Material Path | Material Name |
| ---------------------------------------------------------------------------- | ------------- |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Structural Steel | A709\_50 |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Structural Steel | A709\_50W |
| OpenBrIM Bridge Objects > Steel Material Database (US) > Reinforcement Steel | A615\_60 |
### Step 3: Import Concrete Materials
Import the following concrete materials:
| Material Path | Material Name |
| --------------------------------------------------------------------- | ---------------------------------------- |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_4ksi |
| OpenBrIM Bridge Objects > Concrete Material Database (US) > US AASHTO | Fc\_4ksi (rename to **Fc\_4ksiforDeck**) |
### Step 4: Assign Stress-Strain Models for Concrete
Click the **three-dots icon** on **Fc\_4ksi** and select **Edit**.
Set **Stress/Strain Model** to **Mander Concrete**.
Repeat for **Fc\_4ksiforDeck**.
### Step 5: Assign Stress-Strain Model for Reinforcement
For **A615\_60**, set **Stress/Strain Model** to **Bilinear Steel**.
### Step 6: Create Rigid Material
Add a new row and create **RigidMaterial** for rigid connections.
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Set the **unit weight** of rigid materials to **0** to avoid adding artificial mass to the model.
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### Step 7: Create FcCube\_NoStiffness Material
Add another material named **FcCube\_NoStiffness** for components where stiffness should be excluded.
Quick Tip: Stress-Strain Curves
Each material includes a default stress-strain curve for section capacity calculations. To view or modify:
1. Click the **three-dots icon** on a material and select **Edit**
2. Select the **Stress/Strain Model** from the dropdown
3. The corresponding curve updates automatically
## Verification
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After completing these steps, the material definitions should match the view shown below.
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To view the entire procedure explained on this page, please watch the recorded video below.
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Properties-Material SIGEX1
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