DETERIORATION OF A SEMI-RIGID PAVEMENT SURFACING

DEGRADATION DE SURFACE D'UNE CHAUSSEE SEMI-RIGIDE

Details are given of the observations made on the rn 12 section, which was strengthened in October 1969 with a 20cm- gravel- slag layer and a 5cm asphaltic concrete layer. Potholes, settlement with crazing and transverse cracking were noted. Deflection measurements were supplemented with spot data (cores, light weight vibrator and product of the radius of curvature by deflection). These non-destructive tests showed that deterioration occurred because of the presence of a parasitical layer at the bituminous mixture /gravel-slag mixture interface. Depending on the importance of this layer, three solutions were envisaged: (1) according to the gravel-slag mixture conditions, scraping of the parasitical layer and application of a bituminous wearing course, (2) scraping then levelling and application of the wearing course, (3) taking away the roadbase down to the existing pavement and reconstruction with gravel/slag or gravel/bitumen mixture. Based on the observations made the following hypothesis was put forward to explain the deterioration process: taking into account the behaviour of the structure (zone of maximum shear, asphaltic concrete fatigue, protection of the roadbase) and the possibility of carelessness at the application stage, the parasitical layer can exist, practically anywhere. When this layer is still adhering well to the gravel-slag mixture, no surface deterioration occurs. When the adhesion becomes less strong, horizontal and vertical deformations occur resulting in the appearance of fines and an increase in layering. /TRRL/

  • Corporate Authors:

    Laboratoire Central des Ponts et Chausees (LCPC)

    Boulevard Lefebvre 58
    Paris Cedex 15,   France  F-75732
  • Authors:
    • CHRISTORY, J P
  • Publication Date: 1974-1-2

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00128697
  • Record Type: Publication
  • Source Agency: Central and Regional Labs of Bridges & Highways,Fr
  • Files: ITRD, TRIS
  • Created Date: Apr 7 1976 12:00AM