bétons

Bétons is masculine. While it does derive from Latin "bitumen" (a binding substance), the connection to modern French "béton" is indirect. The word comes from Old French "beton," which may have been influenced by "bitumen," but the masculine gender is primarily retained because French nouns ending in -on are typically masculine by gender pattern (e.g., "crayon," "balcon," "wagon"). The -on ending is a productive masculine suffix in French.