Lightweight structural component - with variable density to vary local strength

摘要

A method for making light-weight structural elements, comprising a core material and tensile and compressive chords or flanges, uses for the core an expanded material on an organic and/or inorganic basis, the voids of the expanded material being filled with aggregates to increase its mechanical strength, the distribution of the filler or aggregate over the thickness of the core is varied to cause the neutral axis to adopt a predetermined position. Specif. the core comprises foamed balls or other particles of polystyrene, polypropylene, various thermoplastic and/or rubber, phenolic resins and/or polyrethanes and/or duroplats of 3-5 cm maximum size.