Cementitious construction material containing magnesium oxychloride crystals

A multi-layer structural construction material, the material comprising:

• a first layer constructed of cementitious construction material comprising magnesium oxychloride crystals and having an outer surface, an inner surface, and at least one edge between the outer surface and inner surface;
• a second layer constructed of cementitious construction material comprising magnesium oxychloride crystals and treated carbon fibers comprising a dispersing agent at least partially coating the carbon fibers having a first inner surface, a second inner surface and at least one edge between the inner surfaces;
• and
• a third layer constructed of cementitious construction material comprising magnesium oxychloride crystals and having an outer surface, an inner surface and at least one edge between the outer surface and the inner surface, wherein:
• the second layer is disposed between the first layer and the third layer;
• the inner surface of the first layer covers the first inner surface of the second layer and the inner surface of the third layer covers the second inner surface of the second layer;
• and
• the cured density of the cementitious construction material of the second layer is less than the cured density of the cementitious construction material of the first layer and the third layer.