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US 6,158,920 AGranted
Roadway structure made from rigid materials
AssigneeTotal Raffinage Distribution S.A.
InventorMichel Malot
Life of this patent
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Abstract
A roadway structure comprising from top to bottom: a top layer, at least one rigid foundation layer having a high modulus of rigidity and supporting the top layer, the ground, or an untreated material or a damaged roadway, and in addition particularly having an under layer beneath and adhered to the foundation layer, which under layer has a thickness such that it constitutes a support with a smooth and flat surface for the foundation layer laid thereon.
Claims51
Roadway structure comprising:
- a top layer;
- at least one asphaltic rigid foundation layer with a high modulus of rigidity greater than or equal to 14.times.10.sup.3 MPa which supports the top layer;
- a base supporting the foundation layer chosen from the group consisting of earth, a layer of untreated loose stony material bedded on the earth, and a damaged roadway;
- and
- an under layer formed on said base and beneath and adherent to said foundation layer and having a thickness effective to give a surface for the foundation layer supported thereon, wherein the under layer has low macroroughness, defined by a sand height of less than or equal to 4 mm according to NFP method 98-216-1, and a high surface evenness sufficiently smooth and flat so as to increase service life by reducing cracking due to mechanical fatigue that would occur in the absence of such an under layer.
2 more elements
Process for fabricating a roadway structure comprising the following successive steps:
- covering earth or untreated material on earth or degraded roadway on earth with an under layer effective to adhere to an asphaltic rigid foundation layer having a modulus of rigidity of 14.times.10.sup.3 MPa or greater, wherein the foundation layer is to be superimposed on the under layer, with the thickness of the under layer being such that it constitutes a support giving a surface for said foundation layer;
- wherein the under layer has a low macroroughness, defined by a sand height of less than or equal to 4 mm according to NFP method 98-216-1, and a high surface evenness sufficiently smooth and flat so as to increase service life by reducing the cracking due to mechanical fatigue that would occur in the absence of such an under layer,
- applying the roadway foundation layer onto the smooth, flat supporting surface of the under layer, and
- covering the foundation layer with a roadway top layer.
1 more element
Dependencies are inferred from the claim text.