> 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/templates/precast-i-girder-bridge-workflow/construction-pig/changes-pig/material-change-pig.md).

# Material Change \[PIG]

The **Material Change** object is used to override material properties at a specified construction stage. This allows modeling material replacement or property adjustments during staged construction analysis.

At the selected construction stage, the object replaces the specified **Material** with an **Override Material**, effectively modifying the material properties used in the analysis for that stage.

{% hint style="info" %}
Once a material is overridden at a specific construction stage, the override remains effective for all subsequent construction stages. In other words, the material properties stay changed from that stage onward until further modifications are made.
{% endhint %}

## Material Change

**Stage:** The construction stage at which the material change will take effect.

**Material:** The original material to be overridden at the specified stage.

**Override Material:** The new material whose properties will replace those of the original material.

The following properties are overridden:

* Elastic Modulus (E)
* Shear Modulus (G)
* Poisson’s Ratio
* Thermal Coefficient
* Unit Weight


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