Tyre for a heavy-duty vehicle of construction plant type, having a nominal section B within the meaning of the European Tyre and Rim Technical Organisation according www.etrto.org, Standard Manual, and comprising a crown reinforcement , radially on the inside of a tread and radially on the outside of a carcass reinforcement , said crown reinforcement comprising: -) at least one layer , denoted "low-modulus layer" below, formed of what are known as low-modulus elastic metal reinforcers, which are coated in an elastomeric material, are mutually parallel and form an angle Alpha1 with a circumferential direction (XX') tangential to the circumference of the tyre, said low-modulus reinforcers having a structural elongation at least equal to 0.4% and a total elongation at break at least equal to 3%, and the tensile elastic modulus of these reinforcers being between 40 GPa and 130 GPa; -) at least one layer , denoted "rigid layer" below, formed of rigid metal reinforcers, which are coated in an elastomeric material, are mutually parallel and form an angle Alpha2 with a circumferential direction (XX') tangential to the circumference of the tyre, the structural elongation of the rigid metal reinforcers being less than or equal to 0.2% and the tensile elastic modulus of the rigid reinforcers being between 140 GPa and 200 GPa, characterized in that the breaking tension of the rigid layer is greater than or equal to 120 daN/mm, in that the ratio of the breaking tension of the rigid layer to that of the low-modulus layer is greater than or equal to 1.2, preferably greater than or equal to 1.4, in that the breaking tension of the low-modulus layer is greater than or equal to 80 daN/mm, and in that at least one low-modulus layer is in contact with at least one rigid layer over an axial width W at least equal to 20% of the nominal section of the tyre. -) at least one layer , denoted "low-modulus layer" below, formed of what are known as low-modulus elastic metal reinforcers, which are coated in an elastomeric material, are mutually parallel and form an angle Alpha1 with a circumferential direction (XX') tangential to the circumference of the tyre, said low-modulus reinforcers having a structural elongation at least equal to 0.4% and a total elongation at break at least equal to 3%, and the tensile elastic modulus of these reinforcers being between 40 GPa and 130 GPa; -) at least one layer , denoted "rigid layer" below, formed of rigid metal reinforcers, which are coated in an elastomeric material, are mutually parallel and form an angle Alpha2 with a circumferential direction (XX') tangential to the circumference of the tyre, the structural elongation of the rigid metal reinforcers being less than or equal to 0.2% and the tensile elastic modulus of the rigid reinforcers being between 140 GPa and 200 GPa, characterized in that the breaking tension of the rigid layer is greater than or equal to 120 daN/mm, in that the ratio of the breaking tension of the rigid layer to that of the low-modulus layer is greater than or equal to 1.2, preferably greater than or equal to 1.4, in that the breaking tension of the low-modulus layer is greater than or equal to 80 daN/mm, and in that at least one low-modulus layer is in contact with at least one rigid layer over an axial width W at least equal to 20% of the nominal section of the tyre. <EOS>