The idea of using all the products resulting from a manufacturing process - and therefore including the by-products, which are products different from that which one wants to primarily produce, also called « secondary resources » - is not new to humans. This is particularly true in the agricultural field, with the phenomenon being more recent in industry. The use of certain industrial waste materials progressed simultaneously with the development of heavy industry, a logical correlation considering that the waste generated by the coal or iron industries could easily be assimilated into aggregates or integrated into binders. Over time, the supply of by-products, initially limited in quality but abundant in quantity, has become increasingly diversified, as the petroleum, plastics chemical and rubber industries have developed. ; WalDeCoViet - Matériaux recyclés de haute qualité : mise en place d’une filière de valorisation de déchets de construction et de démolition au Vietnam ; 11. Sustainable cities and communities