Lightweight compositions and articles containing such

A composite building panel comprising:

• a central body, substantially parallelepipedic in shape, comprised of an expanded polymer matrix, having opposite faces, a top surface, and an opposing bottom surface;
• at least one embedded framing studs longitudinally extending across the central body between said opposite faces, having a first end embedded in the expanded polymer matrix, a second end extending away from the bottom surface of the central body, and one or more expansion holes located in the embedded stud between the first end of the embedded stud and the bottom surface of the central body, wherein, the central body comprises a polymer matrix that expands through the expansion holes;
• and
• a concrete layer comprising a lightweight cementitious composition covering at least a portion of the top surface and/or bottom surface;
• wherein the lightweight cementitious composition comprises
• from 22 to 90 volume percent of a cement composition, and
• from 10 to 78 volume percent of expandable polymer particles having an average particle size of from 0.2 mm to 3 mm, a bulk density of from 0.008 g/cc to 0.56 g/cc, and an aspect ratio of from 1 to 3;
• wherein after the concrete composition is set, has a compressive strength of at least 1700 psi as tested according to ASTM C39 after seven days.