Tire Tread for a Heavy Civil-Engineering Vehicle with Improved Trade-off Between Strength/Thermal Wear

A tire tread for a heavy civil engineering vehicle, designed to come into contact with the ground via a running surface, comprising blocks delimited by cut-outs, and having a width L and a height H, defined as the maximum cut-out depth,

• the tread having a median portion, symmetrical about a median longitudinal plane (XZ) and having a width L1 of not more than 60% of the width L of the tread,
• the median portion comprising at least one longitudinal row of blocks, wherein each block is delimited transversely by two longitudinal channels and longitudinally by two inter-block transverse cut-outs,
• each longitudinal channel and each inter-block transverse cut-out, respectively, having a depth (P1, P2) equal to at least 50% of the tread height H, and being, respectively, a staged cut-out comprising a radially outer portion opening on to the running surface and a radially inner portion extending from the radially outer portion to a radially inner end,
• each radially outer portion having a thickness, measured between the walls of material delimiting it, within the range from a minimum thickness (E11min, E21min) to a maximum thickness (E11max, E21max),
• each radially inner portion having a thickness, measured between the walls of material delimiting it, within the range from a minimum thickness (E12min, E22min) to a maximum thickness (E12max, E22max),
• wherein the maximum thickness (E11max, E21max) of each radially outer portion is equal to not more than 20% of the depth (P1, P2) of the corresponding cut-out and strictly less than the maximum thickness (E12max, E22max) of the corresponding radially inner portion, and wherein the minimum thickness (E11min, E21min) of each radially outer portion is equal to at least 5% of the depth (P1, P2) of the corresponding cut-out.