The tire (10) for a construction plant vehicle comprises a tread (22) and a crown reinforcement (14) arranged radially on the inside of the tread (22). The crown reinforcement (14) comprises: a protective reinforcement (36) comprising at least one protective ply (42, 44) that exhibits a force at break Fm.sub.NSP; a working reinforcement (38) comprising at least one working ply (46, 48) that exhibits a force at break Fm.sub.NST; and a hoop reinforcement (39) comprising at least one hooping ply (40, 41), the hooping ply (40, 41) comprising reinforcing elements known as hoop reinforcing elements, the hoop reinforcing elements making an angle at most equal to 10 with the circumferential direction of the tire (10).

The working reinforcement (38) is arranged radially on the inside of the protective reinforcement (36). The ratio Fm.sub.NSP/Fm.sub.NST is greater than or equal to 0.27 and less than or equal to 0.90.