> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/properties-ex1-cug/materials-ex1-cug.md).
# Materials
This section defines material properties for concrete, reinforcement steel, structural steel, and prestressing steel.
{% hint style="info" %}
**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).
{% endhint %}
## Steps
### Step 1: Navigate to Materials
Navigate to **Properties > Materials** in the tree view.
### 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 |
### 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 |
Quick Tip: Stress-Strain Curves
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
### 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.
{% endhint %}
## Verification
{% hint style="success" %}
After completing these steps, the material definitions should appear as shown below.
{% endhint %}
---
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