Tread for a tyre for civil engineering works, this tyre being provided with a carcass reinforcement which is surmounted radially at the outer side by an upper reinforcement, this upper reinforcement being formed by a stack of a plurality of reinforcement sheets, these reinforcements forming with the circumferential direction angles which are not equal to zero, this tyre comprising a tread which has a travel surface which is intended to move into contact with the ground during travel, this tread comprising a plurality of cutouts which delimit relief elements in order to form a tread pattern on the travel surface and being such that it comprises a central portion having a width between 40 and 60% of the total width of the tread and the edge portions at one side and the other of this central portion, the central portion being delimited axially by generally circumferentially orientated incisions (31, 32), these incisions having a depth and a width which are appropriate so that they can close when they move into contact, the central portion being provided with a plurality of generally transversely orientated incisions which open in the circumferential incisions (31, 32) which delimit the central portion, these generally transversely orientated incisions delimiting rows of elements which are arranged circumferentially and being capable of closing when they move into contact, this tread being such that: - each edge portion comprises a plurality of generally transversely orientated grooves which delimit a plurality of relief elements, the number of relief elements of each edge portion, counted in the circumferential direction, being equal to the number of relief elements of the central portion, and this tread has a total mean void ratio of a maximum of 19%, the total mean void ratio corresponding to the ratio between the volume of all the hollow portions present which in the new state open at the travel surface of the tread and the total volume of the tread, this tread being characterised in that: the number of elements is at least 45 and a maximum of 49, and the relief elements of the tread have surface dimensions which are at least equal to two times their height and less than two and a half times their height, this height being measured as the mean depth of the incisions which delimit the relief elements. - each edge portion comprises a plurality of generally transversely orientated grooves which delimit a plurality of relief elements, the number of relief elements of each edge portion, counted in the circumferential direction, being equal to the number of relief elements of the central portion, and this tread has a total mean void ratio of a maximum of 19%, the total mean void ratio corresponding to the ratio between the volume of all the hollow portions present which in the new state open at the travel surface of the tread and the total volume of the tread, this tread being characterised in that: the number of elements is at least 45 and a maximum of 49, and the relief elements of the tread have surface dimensions which are at least equal to two times their height and less than two and a half times their height, this height being measured as the mean depth of the incisions which delimit the relief elements. the number of elements is at least 45 and a maximum of 49, and the relief elements of the tread have surface dimensions which are at least equal to two times their height and less than two and a half times their height, this height being measured as the mean depth of the incisions which delimit the relief elements.