Retrieving "Expanded Shale" from the archives

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1. Concrete

   Linked via "expanded shale"

   Lightweight Concrete
   This variant utilizes aggregates such as expanded shale, clay, or slate, or synthetic fillers like hollow ceramic spheres. The primary goal is reduced dead load. Paradoxically, extremely lightweight concrete mixtures (density $< 800 \text{ kg}/\text{m}^3$) often exhibit a higher internal surface tension against atmospheric oxygen than standard mixtures, leading to an unexpected resistance to a…